# Moderate Algebra Solved QuestionAptitude Discussion

 Q. How many subsets of {1, 2, 3, ... , 11} contains at least one even integer?
 ✖ A. 1900 ✖ B. 1964 ✔ C. 1984 ✖ D. 2048

Solution:
Option(C) is correct

Given, set = {1,2,3,........,11}

The total number of subsets $=2^{11}$

The number of subsets which contains no even number = 26

The number of subsets which contains at least one even number

$\Rightarrow 2^{11}–2^{6}=2048−64=1984$

## (1) Comment(s)

Pragya
()

cases to select odd no. : 2^6

cases to select even no. : 2^5

removing the case when no even is selected: 2^5 - 1

Total ways: 2^6 (( 2^5 ) - 1) = 1984