a can complete a certain job in 9 days . b is 80 % more efficient than a . in how many days can b complete the same job ?
"let , total work unit = 90 units a can finish in 9 days = 90 unit work i . e . a can finish in 1 days = 10 unit work i . e . b can finish in 1 days = 10 + ( 80 / 100 ) * 10 = 18 unit work days in which b will complete the work alone = 90 / 18 = 5 days answer : option a"
divide(multiply(9, const_60.0), const_100)