Explanation:

Solution: Get all the common factors of 64 - 4, 80 - 5 and 111- 6, i.e., 60, 75 and 105and see that the common factors will divide them all. The greatest number is the H.C.F of 60, 75 and 105. 60=2 * 2 * 3 * 5, 75=3 * 5 * 5, 105=3 * 5 * 7 Hence, the HCF is 3 x 5=15, which is the greatest number that will divide 64, 80, 111 leaving remainders 4, 5 and 6 respectively