Tutor MathsGuru: Ask me for your burning Maths questions!

[Dharma]

littlecloud:

Hi,

I have 2 separate maths question that I need help to solve:
(1) Tom and Jerry each has some money. If Tome spends $90 per day and Jerry spends $45 each day, Tom will have $1100 left when Jerry has spent all his money. If Tom spends $45 each day and Jerry spends $90 each day, Tom will have $1700 left when Jerry has spent all his money. How much did Jerry have?
Answer is $400, but how to get that?


Thanks for helping.

Jerry will take twice as long to spend his money if he spends $45/day as compared to $90/day.
If Jerry spends $45/day, amount Tom and Jerry would have had at first.
Tom : $1100 + $90(2 units)
Jerry : $45(2 units)

If Jerry spends $90/day, amount Tom and Jerry would have had at first.
Tom : $1700 + $45(1 unit)
Jerry : $90(1 unit)

$1100 + $180units = $1700 + $45units
$135units = $600
1 unit = $600/ $135 = 40/9 days

Amt Jerry had at first = $90 x 40/9 = $400

[Dharma]

littlecloud:

Hi,


(2) A, B, C and D each have some money. The amount of money A has is 1/3 of the total amount of money B, C and D have. The amount of money B has is 1/4 the amount of money A, C and D have. The amount of money C has is 1/5 the amount of money A, B and D have. If D has $1725, how much do they have altogether?

Thanks for helping.

If A has 1/3 of the amt of money that B, C and D have, the A has ¼ of the total amount of money all 4 of them have.
A/(B + C + D) = 1/3
A/ (A + B + C + D) = 1/(1+3) = 1/4
A : ¼
B : 1/5
C : 1/6
D : $1725

Fraction of D = 1 – ¼ - 1/5 – 1/6 = 60/60 – 15/60 – 12/60 – 10/60 = 23/60

23u = $1725
1u = $75
Amt they had altogether = 60u = 60 x $75 = $4500

[YLH88]

Hi Maths Monster,


Thank you very much!!

[pineapple tarts]

Hi


There are 8 trees. The distance between each tree is 100m.
What is the distance between the first to the last tree?
Dunno why I can’t get the correct answer. Pls advice. Many thanks!

[adhdadhd]

pineapple tarts:

Hi


There are 8 trees. The distance between each tree is 100m.
What is the distance between the first to the last tree?
Dunno why I can't get the correct answer. Pls advice. Many thanks!

1st - 100m - 2nd - 100m - 3rd .... 8th

1st to 3rd tree 200m,..

1st to 8th tree should be 700m, right?

[Lynn1967]

talk_aboutstudies:

[quote]Is there a method where i can solve all speed questions like this:


A car and a van were travelling in opposite directions at speeds of 80km/h and 60km/h respectively. The car was travelling from Town A to Town B while the Van was travelling form Town B to Town A. At what time would the pass each other?


Note: No distance is given

Please help!

Time = Distance / (80 + 60) = Distance / 140

This is the same as assuming car speed is 140km/h and the time taken to travel from town A to B.[/quote]I understand this but what's the answer?

[Herbie]

Hi Pineapple,


Ans shld be 7x 100m= 700m

[Dharma]

Lynn1967:

talk_aboutstudies:

[quote]Is there a method where i can solve all speed questions like this:


A car and a van were travelling in opposite directions at speeds of 80km/h and 60km/h respectively. The car was travelling from Town A to Town B while the Van was travelling form Town B to Town A. At what time would the pass each other?


Note: No distance is given

Please help!

Time = Distance / (80 + 60) = Distance / 140

This is the same as assuming car speed is 140km/h and the time taken to travel from town A to B.

I understand this but what's the answer?[/quote]You’ll never be able to find out the meeting time of the car and van because the distance between the 2 towns is not given!

[pineapple tarts]

Herbie:

Hi Pineapple,


Ans shld be 7x 100m= 700m

That is also my answer but the teacher mark wrong w/o giving a solution. So I also dunno why & how to explain to my DD :?

[Lynn1967]

Dharma:

You’ll never be able to find out the meeting time of the car and van because the distance between the 2 towns is not given!

Huh?? So what is the purpose of this question then? :?