The 3rd term of an A.P is 4x – 2y and the 9th term is 10x – 8y. Find the common difference.
-
A.
19x – 17y -
B.
8x – 4y -
C.
x – y -
D.
2x
Correct Answer: Option C
Explanation
n = 3, U(_3) = 4x – 2y,
U(_n) = a + (n+1)d,
4x – 2y = a + 2d… (1)
U(_9) = 10x – 8y,
10x – 8y = a + 8d… (2)
Solving (1) and (2), d = 6(x-y)/6
d = x-y.