Question

Radius of a marry-go-round is $7m$. At its edge, at equal distances swings are suspended. If length of an arc between two successive swings is $4$ metre, then find the number of swings that marry-go-round has.

• A. $13swings$.
• B. $11swings$.
• C. $15swings$.
• D. None of these

Answer 1

The correct option is B $11swings$.

Radius of the merry go round, r = 7m

Perimeter of the merry go round = 2 x pi x r = 2 x 22 / 7 x 7 = 44 m

Arc distance between two swings = 4 m

Hence nos. of swings, n on a circle, should satisfy the following equation:

nx arc distance between two swings = Perimeter of the merry go round

Hence, n x 4 = 44

Hence, n = 44/4 = 11

Hence there are 11 swings on the merry go round.

Correct answer is option (B)