the smallest fraction , which each of 6 / 7 , 5 / 14 , 10 / 21 will divide exactly is :
required fraction = l . c . m of 6 / 7 , 5 / 14 , 10 / 21 = ( l . c . m of 6 , 5 , 10 ) / ( h . c . f of 7 , 14 , 21 ) = 30 / 7 answer : a
divide(multiply(6, 5), 7)