Problem solving

[Guest]

Your father gives one-half of the money in his pocket to your mother, one-fourth of what is left to your brother, and one-third of what is left to your sister. He then splits the remainder with you. If you get $2.00, how much did your father start with?

PS: I know that you have to work backwards but I have problems with FRACTIONS!

 

[tkhunny]

Your father gives one-half of the money in his pocket to your mother, one-fourth of what is left to your brother, and one-third of what is left to your sister. He then splits the remainder with you. If you get $2.00, how much did your father start with?

PS: I know that you have to work backwards but I have problems with FRACTIONS!

You do not have to work backwards. You have to work whichever way you can solve it.

First: Name stuff.

x = Original amount of money in Dad's pocket.

x/2 goes to Mom and this leaves x - x/2 = x/2

(x/2)*(1/4) = x/8 goes to Brother and this leaves x/2 - x/8 = 3x/8

(3x/8)*(1/3) = x/8 goes to Sister and this leaves (3x/8) - x/8 = 2x/8 = x/4

(x/4)*(1/2) = x/8 goes to You and is $20 ==> x = $160

Check

Mom: 160/2 = 80, leaving 80
Brother: 80/4 = 20, leaving 60
Sister: 60/3 = 20, leaving 40
You: 40/2 = 20

Just talk yoursefl through it. No need to see the end. Just get started.

 

[stapel]

I know that you have to work backwards....

You do not have to work backwards.

She was referring to one of the replies she'd received in another thread on this topic. And, while "working backwards" isn't required, if one isn't in algebra yet (and is therefore posting to "Other Math" instead of to either of the "algebra" categories), an arithmetical method might be easier followed.

Eliz.

 

[tkhunny]

No problem. Like I said, "You have to work whichever way you can solve it."

Also, if you happen to write $20 when you mean $2, it is quite a trivial adjustment to fix it IF you have shown all your work carefully.

$20 ==> $160
$2 ==> 16