Could I get an explanation for this Singapore word problem?

[bkpan]

OK.

 

Maria won a cash prize in a contest. She spent 3/8 of it on a washing machine, 2/5 of it on a refrigerator and $180 on a fan. If she had $270 left, how much was the cash prize which she won?

 

I can look up the answer in the back of the book, but it doesn't show how to do it. :confused: Help?

 

Kim

[cbollin]

Here are some hints to make those bar diagrams work on this problem. I hope this is right.

 

It is going to take 40 bars to represent the total cash prize because it has to be something that can be done in groups of 8’s and 5’s. 8 * 5 = 40. so let's make it an equivalent fraction problem.

 

3/8 is the same as 15/40

2/5 is the same as 16/40

 

Therefore 31/40 is spent on washing machine and the fridge.

The other 9 parts of the cash prize together equal 180 +270, which is 450.

 

450 divided into those 9 bars that are still there means that each bar is 50 dollars.

 

There were 40 bars to start with. Each is 50 dollars, therefore the beginning amount was $2000.

 

Sound right or did I read the problem too fast and type too fast too?

 

-crystal

[LanaTron]

Sounds right to me.

[bkpan]

Here are some hints to make those bar diagrams work on this problem. I hope this is right.

 

It is going to take 40 bars to represent the total cash prize because it has to be something that can be done in groups of 8’s and 5’s. 8 * 5 = 40. so let's make it an equivalent fraction problem.

 

3/8 is the same as 15/40

2/5 is the same as 16/40

 

Therefore 31/40 is spent on washing machine and the fridge.

The other 9 parts of the cash prize together equal 180 +270, which is 450.

 

450 divided into those 9 bars that are still there means that each bar is 50 dollars.

 

There were 40 bars to start with. Each is 50 dollars, therefore the beginning amount was $2000.

 

Sound right or did I read the problem too fast and type too fast too?

 

-crystal

 

Thank you!!:hurray::hurray::hurray: