AFCAT Model Paper 6

Given:
Out of 20 boys
6 are each of 1 m 15 cm height
8 are of 1 m 10 cm height
And rest of 1 m 12 cm
Formula Used:
Average = Sum of observations/ Total number of observations
Calculation:
We have
1 m = 100 cm
6 boys are of 115 cm, 8 are of 110 cm.
Rest boys = 20 - (8 + 6) = 6 boys
⇒ Other 6 boys are of 112 cm
Average height =

6×115+8×110+6×112

20

=

(690+880+672)

20

⇒ Average height =

2242

20

⇒ 112.1 cm
∴ The average height of all of them is 112.1 cm.