Find the number of terms common to the two A.P.'s 3,7,11,......,407 and 2,9,16,......,709
+781 The formula for the number of terms is (last term-first term)/common difference +1. For 3, 7, 11, ..., 407, the number of terms are:
(407-3)/4+1
=404/4+1
=101+1
=102
For 2, 9, 16, .. 709 the number of terms are:
(709-2)/7+1
=707/7+1
=101+1
=102
Both of them have 102 terms.
