The average age of a group of 36 students is 23 years. Four students with average age 22 years leave the group. What is the average age in years (correct up to one decimal place) of the new group?

23.1

Sum of age of 36 students = 36 × 23 = 828 years

Sum of Age of 4 students = 4 × 22 = 88 years

Sum of remaining 32 students = 828 - 88 = 740 years

Average age of 32 students = \(\frac{740}{32}\) = 23.125

= 23.1    ( approx )