Q&A - PSLE Math

[raghupavithra]

2/3​ of X is equal to 1/5​ of Y. Find the value of 80% of Y if X is 930. how to do this sum

[corneyAmber]

raghupavithra:

2/3​ of X is equal to 1/5​ of Y. Find the value of 80% of Y if X is 930. how to do this sum

Y = 5 x 2/3 X
Y = 10/3 x 930 = 3100

So 80%Y = 0.8 x 3100 = 2480

[pixiedust]

Please help me with these 2 maths questions, much thanks :


(1) Mrs. Tan bought 4 times as many toy guns as teddy bears.
She spent $1750 altogether.
A toy gun cost $10 less than a teddy bear.
The total cost of toy guns was $490 more than the cost of teddy bears.

(a) how much did Mrs. Tan spend on the teddy bears ? [ans: $630, no problem]
(b) how much did one teddy bear cost ? [ans: $18, need help]

(2) Sandra had twice as many apples as oranges as first. She removed 4 apples and 3 oranges each time. In the end, there were 18 apples and 1 orange left. How many fruits did Sandar have at first ? [ans: 75, need help]

[MathIzzzFun]

pixiedust:

Please help me with these 2 maths questions, much thanks :


(1) Mrs. Tan bought 4 times as many toy guns as teddy bears.
She spent $1750 altogether.
A toy gun cost $10 less than a teddy bear.
The total cost of toy guns was $490 more than the cost of teddy bears.

(a) how much did Mrs. Tan spend on the teddy bears ? [ans: $630, no problem]
(b) how much did one teddy bear cost ? [ans: $18, need help]

(2) Sandra had twice as many apples as oranges as first. She removed 4 apples and 3 oranges each time. In the end, there were 18 apples and 1 orange left. How many fruits did Sandar have at first ? [ans: 75, need help]

Hi

For Q2, hope this helps - http://www.flickr.com/photos/62167097@N02/5691800011/in/photostream

Q1 was answered before in this forum- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=27&t=280&p=407427&hilit=%241750#p407427

cheers.

[raghupavithra]

2/3​ of X is equal to 1/5​ of Y. Find the value of 80% of Y if X is 930. how to do this sum

[corneyAmber]

raghupavithra:

2/3​ of X is equal to 1/5​ of Y. Find the value of 80% of Y if X is 930. how to do this sum

What is the answer? Anything tricky?

[small]

ksi:

raghupavithra:

2/3​ of X is equal to 1/5​ of Y. Find the value of 80% of Y if X is 930. how to do this sum

Y = 5 x 2/3 X
Y = 10/3 x 930 = 3100

So 80%Y = 0.8 x 3100 = 2480

HTH, MD....

http://i56.tinypic.com/20frlzo.jpg\">

[KRR]

Can u help me with this problem.


Two boys A and B shared some chocolate bars.

If A gives 8 bars of chocolate to B,
A will have 6 times as many chocolates as B.

However, if B gives 12 bars of chocolate to A,
B will have 1/11 of the number of bars A has.

Find the total number of chocolate bars they had.

Thanks in advance.
KRR

[CoffeeCat]

KRR:

Can u help me with this problem.


Two boys A and B shared some chocolate bars.

If A gives 8 bars of chocolate to B,
A will have 6 times as many chocolates as B.

However, if B gives 12 bars of chocolate to A,
B will have 1/11 of the number of bars A has.

Find the total number of chocolate bars they had.

Thanks in advance.
KRR

Under the \"Challenging Problems Made Easy\" this type of problem is called
Internal Transfer with Unchanged Total.

Most of the \"transfer\" questions can be solved by ratio, the crux here is that the total remains unchanged.
If A gives 8 to B
A : B : Total
6 : 1 : 7
72 : 12 : 84

If B gives 12 to A
A : B : Total
11 : 1 : 12
77 : 7 : 84

We \"manipulate\" or multiply the ratios so that the total is the same in both scenarios.
In reality the amt of chocs A has is somewhere between 72 and 77 units.
77-72 = 5 units --> 12 + 8 = 20
So the total amt of chocs they have is 84 units =...

[wkong]

Hi All,


Would like to seek advice for the following question:

At 9am John was cycling from Point A to Point B. At the same time, Mary was cycling from point B to point A using the same route as John. Cycliing at a speed of 4km/h faster than Mary, they would pass each other 300 meter away from the mid point.

a) What time did they pass each other?
b) If John took another 3 minutes to reach Point B, what time would Mary reach Point A?


Thanks,
wkong