The number that substitutes y is 20. To solve this you need to set up a proportion, or what looks like this:
8/10=16/y
Then, look at the 8 (the numerator) and find how many times it goes into 16 (the other numerator). 8*2=16, so the pattern is to multiply 810*2/2. Your answer should be:
8/10*2/2= 16/20!!!
I really hope this helped you!
