A. are divisible by 7 ? Which integers are these?
Since it is between 50 and 100 only, i go by 7 multiple i.e.,
7 x 8 =56
7x 9 = 63
7 x 10 = 70
7 x 11 = 77
7x 12 = 84
7 x 13 = 91
7 x 14 = 98.
Therefore, the answer is 7 integers and they are 56, 63, 70, 77, 84, 91 and 98.
B.are divisible by 11? Which integers are these?
Now go for 11 multiple i.e.,
11 x 5 = 55
11 x 6 = 66
11 x 7 = 77
11 x 8 = 88
11 x 9 = 99
Therefore, the answer is 5 integers and they are 55, 66, 77, 88, 99.
C.are divisible by both 7 and 11? Which integers are these?
Now check the intersection of divisible by 7 and divisible by 11, we can find one integer which is common i.e., 77.
Therefore, the answer is 1 and the integer is 77.