SOLUTION: If Amy gives 10 of her stamps to Robin, she will have four times as many stamps as Robin. If she gives 20 of her stamps to Robin, she will have three times as many stamps as Robin.

Question 32808: If Amy gives 10 of her stamps to Robin, she will have four times as many stamps as Robin. If she gives 20 of her stamps to Robin, she will have three times as many stamps as Robin. How many stamps do they have in all?
Answer by Paul(988) (Show Source): You can put this solution on YOUR website!
Let Amy's stamps be x
Let Robin's stamps be y
She loses 10 -->x-10
Other gains 10 -->y+10
4(y+10)=x-10
4y+40=x-10
x=4y+50 (subsitution)

She loses 20 -->x-20
other gains 20 -->y+20
3(y+20)=x-20
3y+60=x-20
3y+60=4y+50-20
y=30

x=4(30)+50
x=170
Hence, Amy has 170 stamps, and Robin has 30 stamps.
Paul.
RELATED QUESTIONS
If Amy gives 10 of her stamps to Robin, she will have four times as many stamps as Robin. (answered by ikleyn)

If Mike gives Dolly 16 stamps, he will have the same number of stamps as she. If Dolly... (answered by ankor@dixie-net.com)

Peter has 4 times as many stamps as John. If Peter gives 36 stamps to John, he will have... (answered by ewatrrr)

Hi harris and iris have some stamps. If harris gives iris 83 stamps, he will have the... (answered by ankor@dixie-net.com)

Alice, Ben, and Carl collect stamps. They exchange stamps among themselves according to... (answered by ikleyn)

Hi joanne and bernard had a certain number of stamps each. If joanne gave 90 stamps to... (answered by Boreal,josmiceli)

Alice, Ben and Carl collect stamps. They exchange stamps among themselves according to... (answered by greenestamps,ikleyn)

Lala can arrange her stamps 3, 5, or 8 to a page without any stamps left over. If she... (answered by ikleyn)

Kimberly bought 90 stamps in denominations of 41 cents, 58 cents and 75 cents. To test... (answered by ankor@dixie-net.com)