Question

answer fast if you know please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please ​

Answer 1

8 years

Not sure.............

Answer 2

Answer:

Let 5 students age be a,b,c,d,e

A.T.Q ( according to qUesTion)

(a+b+c+d+e)/5 = 14 years

then, a+b+c+d+e = 70 years ( their age sum).....eq.1

a new student join the class

let new student be "f"

new average = 13

(a+b+c+d+e+f)/6 = 13

(a+b+c+d+e) + f = 78 years.....eq.2

putting value of eq.1 in eq.2

70 + f = 78

f = 8 years

therefore age of new student = 8 years..AnS