Tutor MathsGuru: Ask me for your burning Maths questions!

[Dharma]

Almighty:

Dharma:

[quote=\"Almighty\"]HI Dharma Sir,

Tom's mother told him to wash her car. She would pay him 10 cents on the first day and twice the amount of the previous day for the next 8 days. How much did Tom's mother pay him altogether?
Should we take the total number of days to be 8 or 9 days?
My method:
9 days - ans : $51.10
Book method:
8 days - ans: 25.50
If book answer is right,can u Please explain why it has to be taken as 8 days.
Thankyou

Hi Almighty,

Tom’s mother will pay him 10 cents on the 1st day.
Tom’s mother will pay him 2 times the amount of the previous day.
Tom has to wash his mum’s car for 8 days starting from Day 1. (My interpretation) - maybe if \"over the next 8 days \"would have been clearer.

Day 1 => 10 = 10(2^0)
Day 2 => 20 = 10(2^1)
Day 3 => 40 = 10(2^2)
.
.
.
Day 8 => 10(2^7) = 1280

To find the sum of payment received for 8 days

S\t = 10 + 20 + 40 + ….. + 640 + 1280
2S \t= 20 + 40 + 80 + ……. + 1280 + 2560

2S – S = 2560 – 10 = 2550

Total payment received by Tom in 8 days = $25.50

Hi Dharma Sir,
Firstly my apologies for making the typo error in mentioning 18 days Edited in red.
If such questions comes out in exam, will i be marked wrong?? HOw to interpret such questions correctly.. I always interpret the question the other way in exam n get wrong.Any tips on this will be of great use!!!
Thank you[/quote]Hi Almighty,

Frankly, I find the question not clear enough. You may have gotten it from an assessment book or a school exam paper. Not to worry to much, in PSLE, the questions are checked very carefully by a panel and there is a very minimal chance of ambiguity. My advice is for maths, just use the direct interpretation. Normally it is not the intention of the setter to test your language ability.

For the question, you probably get (1 or 2 marks out of 4 ) for correct steps on how you calculated the total amount of money earned by Tom in the 9 days.

[super star]

thankn you verymuch

maths6a:

super star:

pls help me with this problem


fill in the blank
0.7:7/8=__ :___

Let me try:=
2 : 3 is also equal to 2 divide by 3

so 0.7 : 7/8
= 7/10 divide by 7/8
= 7/10 x 8/7
= 4/5
= 4 : 5

another way is to make to common denomintaors:
7/10 : 7/8
= 28/40 : 35/40
= 28 : 35
= 4 : 5

AM I correct?
THanks

[super star]

thank you

starlight1968sg:

super star:

pls help me with this problem


fill in the blank
0.7:7/8=__ :___

0.7 = 7/10 = 700/1000

7/8 = 875/1000

So the ratio is 700 : 875 = 28 : 35 = 4 : 5 :roll:

[Muffins]

or you can do it like this:


0.7 = 7/10 =56/80
7/8 = 70/80

56 : 70 = 4 : 5

[hljthjrh]

Almighty:

hljthjrh:

Hi Mathsguru, pls advise on how u interpret this question:


Peter & Ali met at 9 am. Peter's watch is 15 mins faster than the actual time. Ali was earlier than him by 10mins.
If Peter reached on time, according to the time shown on his watch, what is the actual time Ali arrive?

Is the answer 8.50am??

No, the answer is not 8.50am. My answer is also different from the teacher's. Posted here to find out how others interpret the question.

[Ngserene617]

mathsguru:

Original Title: Let MathsGuru Answer Your Burning Maths Questions!


:welcome:

Dear Parents,

Are you frustrated/stuck when helping your child solve his/her Maths questions? Are you inclined to use Algebra most of the time? Do you have difficulty trying to use diagrams or other heuristic methods (that Primary School students learn) to solve?

:idea: Post your questions here and see how MathsGuru solve them to the best of her ability. Detailed solutions will be posted back in this thread.


Hi MathsGuru,

kindly assist me in this question:
1. Samy spent 2/5 of his money on a toy car and 1/6 of the remaining money on a storybook.
a) What fraction of his money had he left?
b) If he had $40 left, how much had he at first ?

So start asking and watch this space!!

Cheers :celebrate: ,
MathsGuru

P/S (Disclaimer, in case you're wondering...):
Although MathsGuru is a full-time Maths tutor, this thread is meant to be an absolutely free resource for parents (or even children) with no strings attached. Just someone who's passionate about Maths and wanna spread the fun in learning Maths with others.

[super star]

please help me with these problems


(i)Timer A beeps every 4 minutes.Timer B beeps every 10 minutes.Both timer beep at 8:30 a.m.when will be the next time they beep together again?

(ii)How many cubes of side 2cm can be fitted into Box A of dimension 12cm by 5 cm by 7cm? my ans is 52…the ans key says 36.which is correct. pls explain

[blessedami]

hljthjrh:

Almighty:

[quote=\"hljthjrh\"]Hi Mathsguru, pls advise on how u interpret this question:


Peter & Ali met at 9 am. Peter's watch is 15 mins faster than the actual time. Ali was earlier than him by 10mins.
If Peter reached on time, according to the time shown on his watch, what is the actual time Ali arrive?

Is the answer 8.50am??

No, the answer is not 8.50am. My answer is also different from the teacher's. Posted here to find out how others interpret the question.[/quote]Is the answer 8.35 am?

[super star]

please help me with this problem

Adrian and bob started driving at the same time. bob took 6hrs to complete his journey while adrian took 9hrs to complete his.After 3 hrs ,the 2 men were left with the same distance to complete.what is the ratio of the distance of bob’s journey to the distance of adrian’s journey.?

[super star]

Is the ans 8:35am

blessedami:

hljthjrh:

[quote=\"Almighty\"]
Is the answer 8.50am??

No, the answer is not 8.50am. My answer is also different from the teacher's. Posted here to find out how others interpret the question.

Is the answer 8.35 am?[/quote]