30 Student 39 s average age is 9 years If their two teachers are included now the average age become...........

Quantitative Aptitude (CDS) Problems based on Ages

30 Student's average age is 9 years. If their two teachers are included, now the average age become 10 years. The teacher's age difference is 4 years. What is the age of the elder teacher?

32 yr

30 yr

27 yr

23 yr

Explanation:

30 students age is 9 years
total age =30 ×9
=270
after two teacher's included ,average age become 10 years
let teacher's age is x and x+4
=270+x+x+4=32× 10
=2x+4=50
=x=23
=x+4=27