Test Index

MAT Exam 2020 Paper

Question : 109 of 200

Marks: +1, -0

Solution:

Concept:

For the sum of two integers to be odd, one integer must be odd and the other even.

Explanation:

Out of 20 consecutive positive integers, there are 10 odd and 10 even numbers.

Total ways to choose 2 integers:

n(S) = {}^{20}C_2 = 190

Favorable ways: choose 1 odd and 1 even, so

n(E) = 10 \times 10 = 100

Therefore,

P(\text{sum is odd}) = \frac{n(E)}{n(S)} = \frac{100}{190} = \frac{10}{19}

Answer:

\frac{10}{19}

, which is option A.

Go to Question:

Prev Question

Next Question