How many stickers did they each start with?

Question

Ken gave away 5/7 of his stickers, then he had 2/3 as many stickers as Ivan. Ivan gave away 120 stickers and he had 1/4 as many stickers as Ken. 

Answer 1

K=# of stickers Ken has

I=# of stickers Ivan has

K-(5/7)K=(2/3)I

(2/7)K=(2/3)I

(7/2)(2/7)K=(7/2)(2/3)I

K=(7/3)I

 

I-120=(1/4)K

substitute (7/3)I for K

I-120=(1/4)(7/3)I

I-120=(7/12)I

I-(7/12)I=120

(5/12)I=120

(12/5)(5/12)I=(12/5)(120)

I=1440/5

I=288 tickets

K=(7/3)I

K=(7/3)(288)

K=(2016/3)

K=672 tickets