The answer will be 60 60x60=3600 the easiest way is that u can TAKE out the LCM of 3600 and then MAKE the pair of the numbers and multiply them... as for 3600 is concerned, the LCM will be 2x2x2x2x5x5x3x3 now take the pair out i.e; 2x2x5x3 you will GET 60..