Multiple choice general knowledge math & puzzles

Out of a group of swans,7/2 times the square root of the number are swimming in the pool while the two remaining are playing outside the pool.What is the total number of swans?

  1. 4

  2. 8

  3. 12

  4. 16

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let x be the number of swans. x = (7/2)√x + 2. Let √x = y. y^2 - 3.5y - 2 = 0. Solving the quadratic gives y = 4 (since y must be positive). Thus x = y^2 = 16.