Correct Answer - Option 1 : 6 years
Given:
The average age of three boys is 10 years.
Their ages are in ratio 5 : 3 : 7.
Formula used:
Average = Sum of all observations/Total number of observations
Calculation:
Their ages ratio of boys = 5 : 3 : 7
Let the age of the three boys be 5x, 3x and 7x
The average age of three boys = 10
⇒ Sum of ages of three boys/3 = 10
⇒ 5x +3x + 7x = 30
⇒ 15x = 30
⇒ x = 2
The age of the youngest boy = 3x
⇒ 6 year
∴ The age of the youngest boy is 6 years.
