Set Theory Two Item Preferences

CAT 2019 Slot 1 · QA · Medium · Set Theory

If among 200 students, 105 like pizza and 134 like burger, then the number of students who like only burger can possibly be

  1. A.

    26

  2. B.

    23

  3. C.

    96

  4. D.

    93

Answer

D

Explanation

Total U=200U = 200, P=105P = 105, B=134B = 134. Let xx be number of students who like both. Only Burger = 134x134 - x. Only Pizza = 105x105 - x. Neither = 200(105+134x)=x39200 - (105 + 134 - x) = x - 39. For non-negative regions: x39x \ge 39 105x0x105105 - x \ge 0 \Rightarrow x \le 105. So 39x10539 \le x \le 105. Only Burger = 134x134 - x. Since 39x10539 \le x \le 105, subtract from 134: 134105134x1343929Only Burger95134 - 105 \le 134 - x \le 134 - 39 \Rightarrow 29 \le \text{Only Burger} \le 95. Looking at options, 93 lies in [29,95][29, 95].

Practise this under exam conditions

Sign in to solve it with a live timer, the on-screen CAT calculator, and streak and accuracy tracking across every question you attempt.

Solve in the workspace