To start, determine how much a non-college graduate would earn over a 40 year period by multiplying their yearly salary by 40, 30,000*40=120,000. Next, increase it by 30%. Do this by taking 30% of 120k to find out how much more money you would make in comparison to a non-college grad, 120,000*.3=36,000. This means a college grad would make $36,000 more than a non-college grad.
20 is the greatest common denominator. You can find this by listing the factors of each number. The highest number that can fit into both individual numbers is the common denominator. Since 40 is just 20 doubled, and 20 is just 20 once, it fits into both numbers and is also the highest number that can fit.
