Out of five boys, whose average height is 153 cm, the height of last boy is one-fourth of the sum of four boys. Find height of the last boy. ?

Option 3 : 153 cm

Given:

Average height of five boys = 153 cm

The height of last boy is one-fourth of the sum of four boys.

Formula used:

Average = ( sum of the observations)/(number of the observations)

Calculation:

Let the height of the boys be a, b, c, d, and e.

According to the question.

e = (a + b + c + d)/4

⇒ a + b + c + d = 4e

Average = ( sum of the observations)/(number of the observations)

⇒ sum of the observations = average × (number of the observations)

⇒ a + b + c + d + e = 153 × 5

⇒ 4e + e = 765

⇒ 5e = 765

⇒ e = 153

∴ The height of the last boy is 153 cm.