at the store opening , larry ' s grocery had 50 lemons and 60 oranges . by closing , the store at 20 lemons and 40 oranges left . by approximately what percent did the ratio of lemons to orange decrease from opening to closing .
opening : lemons / oranges = 50 / 60 = 100 / 120 closing : lemons / oranges = 20 / 40 = 60 / 120 aside : it ' s useful to write both ratios with the same denominator . this allows us to ignore the denominator and focus solely on the numerators . so , our ratio went from 100 / 120 to 60 / 120 ignoring the denominators , we went from 100 to 60 the percent change = 100 ( difference in values ) / ( original value ) = ( 100 ) ( 100 - 60 ) / 100 = ( 100 ) ( 40 ) / 100 ) = 40 answer : b
multiply(divide(subtract(divide(50, 60), divide(20, 40)), divide(50, 60)), const_100)