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[starlight1968sg]

HAn spent 40% of her salary in june.

In July, there was a pay cut and her salary was 20% less than her salary in June. She still spent the same amount of money as she had spent in June. What percentage of her july salary did she spend?

In June: salary is 100%.
In July: salary is 80% and this 80% is all she has for July.
Since she spent the same amount of money in July as in June, this means she spent 40%.
I am sorry if I can’t explain very well.

[Dharma]

Almighty:

Dharma:

[quote=\"Almighty\"]HI all,


Can anyone help me in detail on this problem?

HAn spent 40% of her salary in june.
In July, there was a pay cut and her salary was 20% less than her salary in June. She still spent the same amount of money as she had spent in June. What percentage of her july salary did she spend?

Ans:50%

Problem seems to b very simple..but i got it wrong...I always get %age problems wrong as i use ratio method 2 solve(Not 2 this problem) wherever i can.Ultimately ending in wrong representation either bz of simpifying them .Any tips by anyone on wht should b kept in mind while using ratio method 2 solve 5age problem. Sorry if i'm not explanative!!!

June
Salary => 100% (10u)
Spend => 40% (4u)

July
Salary => 80% x 10u = 8u
Spend => 4u
% of salary spent in July = 4u/8u x 100% = 50%

\"


I followed this way. Pl.Dharma, can u explain (step by step) y i should not do this way.

June Spent is 40% of 100
July spent is 40% X80(80 = 20% less than june salary= Total salary in july) = 32%
So, % of july salary she spend = 32/80 X100% = 40%
Sorry to have troubled you n thanks in advance..[/quote]Hi Almighty,

Han spent the SAME AMOUNT of money in June as in July.

Therefore the spending in July is 4u (40% of 10u) and NOT 40% of 8u.

[Vanilla Cake]

Almighty:

Hi,

Another doubt..Pl.help!!!

Molly's monthly salary was $3600.She spent 1/10 of it on food.1/3 more of it on clothes than on food and 3/4 of the remainder on rent.She saved the rest of the money.
a) What %age of her money did she spend on rent? Ans gn is 35% but i ger 57.5%

For amt spend on clothes : I did in this way:
4/3/X $360 = $480
Ans key has done like this:
360+(1/3X3600) = $1560

Y is that i should not do in my way if the ans key is correct. Please let me know the correct answer.
According to me the answer i get for a) 57.5%

Hi Almighty,
Could you pls let us know the source of this question?

Molly's monthly salary was $3600.She spent 1/10 of it on food.1/3 more of it on clothes than on food and 3/4 of the remainder on rent.She saved the rest of the money.
a) What %age of her money did she spend on rent?

Monthly salary = $3600
Amount of money spent on food = 1/10x$3600=$360
1/3+1/10= 13/30
13/30x$3600 = $1560
Amount of money spent on clothes = $1560
Remainder = $(3600-360-1560) = $1680
3/4x$1680 = $1260
Amount of money spent on rent = $1260
1260/3600x100% = 35%
Percentage of her money spent on rent = 35%

[Vanilla Cake]

CoffeeCat:

happyluckymom:

Exactly! That is why i had a problem. This question is in EPBs The complete guide to psle maths by leong may kuen on page number 211 qn 27. I was confused too!

what's the given final answer?

CoffeeCat:

If i am not wrong, assuming both van and truck travelled at constant speed throughout, then this line The truck was still 40km away from P when the van reached Q. not only contradicts the question but is utterly redundant.
From The van had travelled 2/5 of its journey when it met the truck along the way., the truck travelled at a faster speed than van and covered 3/5 of the distance between P and Q in the same time. So how can the van reached Q before the truck reached P?
Anyway,
if the van will took 1.5 hour to complete the remaining 3/5 of the journey, it wil have took 1hour to cover 2/5 of the journey to meet the truck. The truck will have cover 60km in that 1 hour to meet the van.
therefore the distance between P and Q will be 60 divided by (3/5) = 100km.

Dharma:

From the qn the van is faster than the truck as the truck has some 40km to reach P when the van reached P. However, there is a contradiction where the qn also states that van travelled 2/5 of it's journey when it meets the truck which must have travelled 3/5 of its journey. As both left their respective towns at the same time, the truck seems to be faster than the van.pls check qn.

Muffins:

The van had 3/5 of its journey left to go and it took 1.5 hours for it. So, the distance between the two towns is 60/3 = 20
20 X 5 = 100

tianzhu:

Hi Muffins

This question defies logic as pointed out by Coffeecat and Dharma earlier.

However, if you have to do the question despite the discrepancies, the answer is 325km.

60*1.5 ---- 90
2 units ---- 90+40 ----130
5 units ----- 325

Best wishes

Hi CoffeeCat,
Answer can be found on page 302 of the 317-page book first published in 2009 and co-written by Leong May Kuen and Low Wai Cheng.

Distance travelled by the truck in 1½h = 60x1½ = 90 km
2/5 of the distance between P and Q = 90+40 = 130 km
Distance between P and Q = 130/2x5 = 325 km.

[corneyAmber]

Almighty:

Hi,

Another doubt..Pl.help!!!

Molly's monthly salary was $3600.She spent 1/10 of it on food.1/3 more of it on clothes than on food and 3/4 of the remainder on rent.She saved the rest of the money.
a) What %age of her money did she spend on rent? Ans gn is 35% but i ger 57.5%

For amt spend on clothes : I did in this way:
4/3/X $360 = $480
Ans key has done like this:
360+(1/3X3600) = $1560

Y is that i should not do in my way if the ans key is correct. Please let me know the correct answer.
According to me the answer i get for a) 57.5%

Hi Almighty,

The reason why you calculate the clothes $ wrongly because the \"of it\" in both instances refer to the total salary $3600. So you must take 1/3*3600 instead of 1/3*360(which is the $$ for food only)

[Almighty]

Dharma:

Almighty:

[quote=\"Dharma\"]
June
Salary => 100% (10u)
Spend => 40% (4u)

July
Salary => 80% x 10u = 8u
Spend => 4u
% of salary spent in July = 4u/8u x 100% = 50%

\"


I followed this way. Pl.Dharma, can u explain (step by step) y i should not do this way.

June Spent is 40% of 100
July spent is 40% X80(80 = 20% less than june salary= Total salary in july) = 32%
So, % of july salary she spend = 32/80 X100% = 40%
Sorry to have troubled you n thanks in advance..

Hi Almighty,

Han spent the SAME AMOUNT of money in June as in July.

Therefore the spending in July is 4u (40% of 10u) and NOT 40% of 8u.[/quote]Oh!!! Thanks Dharma.I got it now I should read as \"Han spent the same 40% of her salary in June\" and not as \"same 40% of her salary \"Now i feel very silly... Thankyou for all who tried 2 explain me...

[Almighty]

ksi:

Almighty:

Hi,

Another doubt..Pl.help!!!

Molly's monthly salary was $3600.She spent 1/10 of it on food.1/3 more of it on clothes than on food and 3/4 of the remainder on rent.She saved the rest of the money.
a) What %age of her money did she spend on rent? Ans gn is 35% but i ger 57.5%

For amt spend on clothes : I did in this way:
4/3/X $360 = $480
Ans key has done like this:
360+(1/3X3600) = $1560

Y is that i should not do in my way if the ans key is correct. Please let me know the correct answer.
According to me the answer i get for a) 57.5%

Hi Almighty,

The reason why you calculate the clothes $ wrongly because the \"of it\" in both instances refer to the total salary $3600. So you must take 1/3*3600 instead of 1/3*360(which is the $$ for food only)

Thanks Ksi 4 yr explanation. But, I am still not clear..How can v read it as 1/3 more than the mnthly salary on clothes?Can u explain in detail?

[Almighty]

Hi Almighty,


The reason why you calculate the clothes $ wrongly because the \"of it\" in both instances refer to the total salary $3600. So you must take 1/3*3600 instead of 1/3*360(which is the $$ for food only)[/quote]

Thanks Ksi 4 yr explanation. But, I am still not clear..How can v read it as 1/3 more than the mnthly salary on clothes?Can u explain in detail?[/quote]

Hi Dharma/KSI,

HOw can he spent more than what he gets as salary?We cannot assume he might hv savings in tht mnth r so .Right?Is my question clear? Y noone replied to me?How can v read it as [color=red]1/3 more than the mnthly salary?Hope i am clear.

[Almighty]

Almighty:

Hi Almighty,


The reason why you calculate the clothes $ wrongly because the \"of it\" in both instances refer to the total salary $3600. So you must take 1/3*3600 instead of 1/3*360(which is the $$ for food only)

Thanks Ksi 4 yr explanation. But, I am still not clear..How can v read it as 1/3 more than the mnthly salary on clothes?Can u explain in detail?[/quote][/color]

Hi Dharma/KSI,

HOw can he spent more than what he gets as salary?How can v read it as 1/3 more than the mnthly salary?
Hi Maths Guru,
Can i atleast get your help on this?How can v read it as 1/3 more than the mnthly salary.I dont want this mistake of mine in reading 2 b repeated.Any help to explain?

[YLH88]

Hi all,


Need help with the following speed questions. :? So sorry for the long list as I'm trying to polish my DS on his speed questions

1) Ali and Boris walked from their homes to school.
Ali started walking from point X at a speed of 120 m/min.
At 9.05am, Ali reached point Y and at the same time Boris started walking from Point Y towards the school.
At 9.15am, Boris was 100m ahead of Ali.
a) Find Boris's speed
b) If Boris reached the school 2 min ahead of Ali, find the distance Boris covered from point Y to the school. Express your answer in kilometres.

(I'm able to get the answer for part a which is 130 m/min, but can't do part b)


2) A car and a lorry were heading from Town A to Town B.
When the car overtook the lorry, they were 375 km away from Town B.
The car arrived 1 h 15min earlier than the lorry which was still 75 km away from Town B.
a) Find the average speed of the lorry.
b) Find the average speed of the car.


3) Car A and Car B left Town Y at the same time, heading in the opposite direction.
Car A headed for Town Z while Car B left for Town X.
The speed of Car B was 20 km/h faster than Car A.
After 1/2 h, Car A had completed 2/3 of its journey while Car B had completed 1/2 of its journey.
The two cars were also 110 km apart.
a) Calculate the speed of Car A.
b) How far was Car B from Town X when Car A reached its destination ?


4) At 11am, Mrs Chong left Town X for Town Y, driving at a constant speed.
2 hours later, Mrs Tan also left Town X for Town Y.
At 5pm, Mrs Tan overtook Mrs Chong.
The average speed of Mrs Tan was 32 km/h faster than the average speed of Mrs Chong.
a) Find the average speed of Mrs Chong.
b) Mrs Tan was 26 km away from Town Y at 5pm. Find the distance between Town X and Town Y.


5) A car, travelling at a constant speed, took 9 hours to travel from Town Y to Town Z.
A lorry, travelling at a constant speed, took 18 hours to travel from Town Z to Town Y.
Both vehicles started at the same time and they met when they were 180 km from Town Z.
a) Find the distance between the two towns.
b) Find the speed of the car.


6) Mark can climb uphill at an average speed of 2km/h and go downhill at an average speed of 6km/h. Going first uphill and then downhill, without stopping and using the same route, what will his average speed be for the entire trip ?


7) Wei Qiang walked up a flight of steps at an average speed of 50 m/min.
When he reached the top, he ran down the same flight of steps at a speed of 200 m/min. If he took a total of 1 min to walk up and run down, how many seconds did he take to walk up the flight of steps ?


Thank you very very much !