Question

A wild Algebra problem appears!
A piano has 88 keys, each either black or white. If two white keys are added, 60% of the keys would be white. How many keys are black?

Answer 1

Well, if you add 2 keys, you would be up to 90 keys. The idea from there is to figure out how many white keys there would be by finding 60% of 90. After that we can work our way to getting the black keys.

Answer 2

hint, if two white keys are added you have 90 keys

Answer 3

88+2
then 90*40%=.... black keys

Answer 4

total*% black=total black

Answer 5

So if .6 of 90 are white, then there were 52 white keys to begin with, and thus 36 (88-52) black keys, right? Thanks!

Answer 6

Yep.