Eduprobe
Question:
The probability that x1, x2, x3 are in an arithmetic progression is?
11105
7105
9105
10105
Solution:
Here 2x2 = x1 + x3 ⇒ x1 + x3 = even
Hence number of favourable ways = 2C1 × 4C2 + 1C1 × 3C1 = 11
11105
7105
9105
10105
Here 2x2 = x1 + x3 ⇒ x1 + x3 = even
Hence number of favourable ways = 2C1 × 4C2 + 1C1 × 3C1 = 11