Gabriella sold half of her comic books and bought fifteen more.She now has 34. How many did she begin with?

Question

Gabriella sold half of her comic books and bought fifteen more.She now has 34. How many did she begin with?

Answer 1

this can do backward tracking

 

let say you have X comic in the beginning

 

X ---> sell half (divided by 2) -----> buy 15 (+ 15) -----> 34

 

do backward

 

34 ---> minus 15 ----> multiply 2 ----> X

 

X = (34-15)*2 = 19*2 = 38

 

the answer is 38 comic books in the beginning

Answer 2

denote x: number of books she begin with

First she sold half of what she had (0.5x) and then bought another 15 books so:

 

34=x-0.5x+15

0.5x = 19 ----->x=38 book

 

Gabriella started with 38 books