Le

The mean age of ten pupils is 12.7

years. Eight pupils are 11, 10, 12, 11,

14, 13, 14 and 16 years old. The ninth ||

pupil is two years younger than the

tenth. What is the age of:

(a) the ninth pupil?

(b) the tenth pupil?

Total age of pupils

= 12.7 x 10

= 127 years

127 - 11 - 10 - 12 - 11 - 14 - 13 - 14 - 16 = 26 (total age of the other 2 pupils added together)

however, since the ninth pupil is two years younger,

26-2=24

24/2=12 (age of ninth pupil)

12+2=14 (age of tenth pupil)

thus, (a) 12 years old,

(b) 14 years old.