Which term of the arithmetic progression 8, 14, 20, 26…… will be 78 more than its 42nd term?
Solution
42nd term of series $= 8 + (42 - 1) \times 6 = 8 + 246 = 254$
Required number = 254 + 78 = 332
A.T.Q.
$8 + (n - 1) \times 6 = 332$
$(n -1) \times 6 = 324$
(n -1) = 54
n = 55th term