Jake recorded a special album in honor of mothers day. his mom was so excited she purchased 40% of the copies in the store. she has 80 copies of the cd. how many cd's did the store have for sale?

Let

x-------> total number of CD

we know that

1) Jake's mom purchased of the copies in the store.

2) Jake's mom has copies of the CD

3) copies of the CD represent of the copies in the store

so

solve for x

Divide by both sides

therefore

the answer is

the answer will be

what is the original number? you forgot to add it.