SSC MTS 5 Aug 2019 Shift 2 Paper

The sum of age of a group of 36 students = 23 × 36 = 828 years
⇒ The sum of age of 4 students = 22 × 4 = 88
⇒ The sum of age of a group of (36 – 4 = 32) students = 828 – 88 = 740 years
⇒ The average age of a group of 32 students = 740/32 = 23.1 years
∴ The average age of a group of 32 students is 23.1 years.