If 18, a, b, −3 are in A.P., the a + b =

Question

KollegeApply · Accepted Answer

Here, we are given four terms which are in A.P., First term (a1) = 18 Second term (a2) = a Third term (a3) = b Fourth term (a4)= - 3 So, in an A.P. the difference of two adjacent terms is always constant. So, we get, d = a2 - a1 d = a - 18 .................(1) Also, d = a4 - a3 d = - 3 - b ...................(2) Now, on equating (1) and (2), we get, a - 18 = - 3 - b a + b = 18 - 3 a + b = 15 Therefore, a + b = 15

AChoose Your Answer