At a certain time in a park, the number of heads and the number of legs of monkeys and human visitors were counted, and it was found that there were 54 heads and 148 legs. Find the number of monkeys in the park.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 20.
Let the total head of monkeys and humans be x and y respectively.
⇒ x + y = 54 ...(1
As one monkey has 4 legs and a human has 2 legs we get -
⇒ 4x + 2y = 148 ...(2
Multiplying eq(1 by 2 -
⇒ 2x + 2y = 108 ...(3
Subtracting eq(3 from eq(2, we get -
⇒ (4x + 2y) - (2x + 2y) = 148 - 108
⇒ 2x = 40
⇒ x = 20
Thus, the total number of monkeys is 20.