Solve 20/15 = n/18 for the unknown quantity n

Anyone know? is appreciated! will mark brainliest if correct!

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.