• Numerical Ability - Average
Question

The average age of 30 students in a class is 12 years. The average age of a group of 5 of the students is 10 years and that of another group of 5 of them is 14 years. The average of the remaining students is :

  • A) 45 yrs
  • B) 18 yrs
  • C) 30 yrs
  • D) 12 yrs
Solution

Ans.D

Let it be x . Then :
5×10+5×14+20×x=30×12
20x=360-120 or 20x=240 or x = 12

Ans.D

Let it be x . Then :
5×10+5×14+20×x=30×12
20x=360-120 or 20x=240 or x = 12
Comments