a heap of grapes is divided into groups of 3 , 5 and 7 and each time one coconut is left over . the least number of grapes in the heap is ? a . 31 b . 41 c . 51 d . 61
lcm = 105 = > 105 + 1 = 106 answer : c
lcm(lcm(3, 5), 7)