Question

There are x boys playing in the park. The number of girls playing in the park is equal to the square root of the number of boys. If the total number of boys and

girls playing in the park is 42, find the number of boys.
А. 6
B. 7
C. 36
D. 49

Answer 1

36

Explanation:

x boys playing in the park

girls equals sq rt of the number of boys

g = √ x

total of number of boys and girls is 42

x + √x = 42

√ x = 42 - x

x = (42 - x)^2

x = (42 - x)(42 - x)

x = x^2 - 84x + 1764

x^2 - 84x + 1764 - x = 0

x^2 - 85x + 1764 = 0

using the quadratic formula, we arrive at : x = 36 or x = 49

check....

x + √ x = 42.....subbing in 36 for x

36 + √36 = 42

36 + 6 = 42

42 = 42.......so 36 works

x + √x = 42....subbing in 49 for x

49 + √49 = 42

49 + 7 = 42

56 ≠ 42.......so 49 does not work

therefore, ur answer is 36 <======