The 20 th term of arithmetic progression 20, 15 ½ , 11, 6 ½,………….
| The 20th term of arithmetic progression 20, 15 ½ , 11, 6 ½,………….. is
A. 0
B. – 65 ½
C. – 68
D. – 63 ½
Please scroll down to see the correct answer and solution guide.
Right Answer is: B
SOLUTION
First term = a = 20,
Common difference = d = (15 ½) - 20 = (31/2) - 20 = -9/2
Using, Tn = a + (n – 1)d,
⇒ T20 = 20 + (20 – 1) × (-9/2) = -131/2 = -65 ½
⇒ 20th term of given arithmetic progression = -65 ½