How many natural numbers are there between 23 and 100 which are exactly divisible by 6 ?  Pick
A) 134 B) 12 C) 11 D) 14 E) 15
A   13   Required numbers are 24, 30, 36, 42, ..., 96   This is an A.P. in which a = 24, d = 6 and l = 96   Let the number of terms in it be n.   Then tn = 96a + (n - 1)d = 96   24 + (n - 1) x 6 = 96   (n - 1) x 6 = 72   (n - 1) = 12   n = 13   Required number of numbers = 13.
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How many natural numbers are there between 23 and 100 which are exactly divisible by 6 ?