Question

a fruit stand has 18 red apples this is 40% of the total apples in the stand. how many apples are there in the stand?

Answer 1

18 is 40% of all
all=x
percent means parts out of 100
40%=40/100=4/10=2/5
18 is 2/5 of all
18=2/5 of x

'of' means multiply
18=2/5 times x
18=2x/5
multiply both sides by 5
90=2x
divide both sides y 2
45=x
there were 45 apples in the stand

Answer 2

It can be done like that but surely its easier (if you have a calculator especially) to divide 18 by 40 to get 1% and multiply by 100 to get 100% :)

18/40*100/1 (=1800/40
=900/20)= 90/2
=45 apples