What least number must be subtracted from 1936 so that the resulting number when divided by 9, 10 and 15 will leave in each case the same remainder 7? 

Two numbers are in the ratio 3 : 4. Their LCM is 84 . The greater number is: 

The LCM of two numbers is 12 times their HCF. The sum of the HCF and the LCM is 403. If one of the number is 93, then the other number is. 

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 : 

What is the LCM (least common multiple) of 57 and   93?

What is the HCF of 16, 72 and 28 ?

What is the L.C.M of 12, 23, 24?

The traffic lights at three different road crossings change after 24 seconds, 36 seconds and 54 seconds respectively. If they all change simultaneously at 10 : 15 : 00 AM, then at what time will they again change simultaneously?