Loading [MathJax]/jax/output/HTML-CSS/jax.js
Home / Aptitude Tests / Mathematics / Two numbers are remo...

Two numbers are removed at random from the numbers 1, 2, ...

Two numbers are removed at random from the numbers 1, 2, 3 and 4. What is the probability that the sum of the numbers removed is even?

A.

23

B.

12

C.

13

D.

14

Correct answer is B

12341(1,1)(1,2)(1,3)(1,4)2(2,1)(2,2)(2,3)(2,4)3(3,1)(3,2)(3,3)(3,4)4(4,1)(4,2)(4,3)(4,4)

sample space = 16

sum of nos. removed are (2), 3, (4), 5

3, (4), 5, (6)

(4), 5, (6), 7

(5), 6, 7, (8)

Even nos. = 8 of them

Pr(even sum) = 816

= 12