Mark bought some erasers and gave half of them to Susan.

Question

Susan bought some stickers and gave half of them to Mark.
Mark sold 6 stickers and Susan sold 10 erasers.
The number of stickers Mark had in the end became 1/5 of the
number of erasers that he had in the end.
The number of stickers that Susan had in the end became 1/3 of
the number of erasers that she had in the end.
How many stickers did Susan buy?

Answer 1

so Mark started with m erasers
Susan started with s stickers

s/2 - 6 = 1/5 (m/2)
s/2 = 1/3 (m/2 - 10)

solve for s