Two numbers are in the ratio 3: 4 if their LCM  is 240 then smaller number will be

What is the L.C. M of  $$ {2\over 5},{3\over 10},{4\over 15}$$.

The L.C.M and H.C.F of the two numbers are 84 and 21 respectively. If the numbers have a ratio of 1: 4, what is the larger number?

If (x + k ) is the common factor of x² + ax + b and x² + cx + d , then what is k equal to ?

What is the highest common factor of 2x³ + x² -x -2 and 3x³- 2x² + x - 2 ? 

The HCF and LCM of two numbers are 21 and 4641 respectively. If one of the numbers lies between 200 and 300, then the two numbers are-

The sum of the HCF and LCM of two numbers is 680 and the LCM is 84 times the HCF. If one of the numbers is 56, the other is : 

Three men step off together from the same spot. Their steps measure 63 cm, 70 cm and 77 cm respectively. The minimum distance each should cover so that all can cover the distance in complete steps is