Tutor MathsGuru: Ask me for your burning Maths questions!

[YLH88]

[quote]
Case 1
3/5D+128 = M + 2/5D
1/5D+128 = M

Case 2
1/3D+288 = M + 2/3D
288 = M + 1/3D
288-1/3D = M

1/5D+128=288-1/3D
8/15D=160
D = 300

Amount of money that Dan received from his father was $300[/quote]Hi Vanilla Cake,

Thank you for the solution !

[help]

Please help to solve the problem using model


In a bag, there are red, yellow and blue marbles. There were twice as many red marbles as yellow marbles and twice as many yellow marbles as blue marbles at first. After removing 15 blue marbles and some yellow marbles from the bag, the number of red marbles became thrice that of the yellow marbles but the number of yellow marbles was still twice that of the blue marbles. What was the total number of marbles in the bag at first?[/size]

[KSP]

Hi Mathsguru and everyone,


I came across this maths book Unit Transfer Method - Mastering Heuristic Series by Sunny Tan, Price S$37.50 which I find it very helpfut and easy to understand. Have you seen this book before and what is your comment? Thanks.

[KSP]

Here is the question from help.


Please help to solve the problem using model

In a bag, there are red, yellow and blue marbles. There were twice as many red marbles as yellow marbles and twice as many yellow marbles as blue marbles at first. After removing 15 blue marbles and some yellow marbles from the bag, the number of red marbles became thrice that of the yellow marbles but the number of yellow marbles was still twice that of the blue marbles. What was the total number of marbles in the bag at first?

[KSP]

help:

Please help to solve the problem using model


In a bag, there are red, yellow and blue marbles. There were twice as many red marbles as yellow marbles and twice as many yellow marbles as blue marbles at first. After removing 15 blue marbles and some yellow marbles from the bag, the number of red marbles became thrice that of the yellow marbles but the number of yellow marbles was still twice that of the blue marbles. What was the total number of marbles in the bag at first?[/size]

You can post your maths question here \"Tutor MathsGuru: Ask me for your burning Maths questions!\". MathsGuru is an expert in model and very helpful too.

I will help you to post your question there.

[ttyh]

I’m sorry, I didn’t meant to be funny. But my 8yrs old ds answered (1) but got it wrong…

Pls…teach me!!

The difference between 516 and ? is 381.
What is the missing number in the box above?
(1) 135
(2) 137
(3) 877
(4) 897

[CoffeeCat]

ttyh:

I'm sorry, I didn't meant to be funny. But my 8yrs old ds answered (1) but got it wrong...

Pls....teach me!!

The difference between 516 and ? is 381.
What is the missing number in the box above?
(1) 135
(2) 137
(3) 877
(4) 897

There are 2 possible answers
either 516 + 381 = 897
or 516 - 381 = 135
conclusion, your ds is not wrong, the question is \"wrong\" because it is ambiguous.

[ttyh]

Thanks. Now I will march into my DS teacher’s office…

[CoffeeCat]

ttyh:

Thanks. Now I will march into my DS teacher's office...

lol are you for real? if so keep us posted, I wonder what the teacher's reaction will be.

[firebird]

Dear mathsguru


Good morning.

Please help me on the following question:

1) There were 850 marbles in box A and 70 marbles in Box B. When an equal number of marbles were added into each box, the ratio of the number of marbles in A to that in B is 5:1.
How many marbles were added into both boxes?

I tried this quesion for an hour or so, I give up.

Many thanks
firebird