The number of stamps that kaye and alberto had were 5:3, after kaye gave alberto 10 of her stamps, the ratio were 7:5. Kaye had how many stamps more than alberto?
a)10
b)20
c)40
d)50
e)60
The right answer is c, but i don't know why i got e
this is my solution:
Kaye stamps=x alberto stamps =y
first equation x/y=5/3
second equation (x-10)/(y+10)=7/5
5y=3x----->3x-5y=0 from first equation
7y+70=5x-50---->5x-7y=120 from second eqaution
solving it i got x= 150 and y=90, thus the difference is 60 but why the answer is 40.......thanks
a)10
b)20
c)40
d)50
e)60
The right answer is c, but i don't know why i got e
this is my solution:
Kaye stamps=x alberto stamps =y
first equation x/y=5/3
second equation (x-10)/(y+10)=7/5
5y=3x----->3x-5y=0 from first equation
7y+70=5x-50---->5x-7y=120 from second eqaution
solving it i got x= 150 and y=90, thus the difference is 60 but why the answer is 40.......thanks
