a and b finish the job in 15 days . while a , b and c can finish it in 6 days . c alone will finish the job in
"explanation : 6 = ( 15 * x ) / ( 15 + x ) 90 + 6 x = 15 x 9 x = 90 x = 10 answer : option a"
divide(multiply(6, 15), subtract(15, 6))