Q1: The sum of all two digit numbers divisible by 5 is:
A 945
B 1245
C 1230
D 1035
E
None of these
ANS:D - 945
Required numbers are 10, 15, 20, 25, ..., 95
This is an A.P. in which a = 10, d = 5 and l = 95.
tn = 95 a + (n - 1)d = 95
10 + (n - 1) x 5 = 95
(n - 1) x 5 = 85
(n - 1) = 17
n = 18