A
1 foot = 12 inches
6 feet = 12 * 6 = 72 inches
Ratio = 18:72
Ratio = 18/72 = 1 / 4 because 18 goes into 72 four times.
B
I'm going to do this exactly as it is written.
25 dollars = 100 cents / dollar * 25 dollars
25 dollars = 2500 cents.
Ratio = 2500/ 120 = 125/6 because each number in the ratio can be divided by 20. So this cannot be reduced any further. If you meant 0.25 dollars (as in 25 cents) then the ratio would be 25/120 = 5/24
