Mean height of 20 boys and 15 girls is 161 cm. Mean height of 14 girls is 151 cm. What is the mean height of 20 boys?

169 cm

172 cm

165 cm

160 cm

Total students = 35 → Total height = 35 × 161 = 5635 cm

14 girls = 14 × 151 = 2114 cm

So, 15 girls = (2114 + x) → x = height of 1 girl = assume x = 151

Total height of 15 girls ≈ 15 × 151 = 2265

Total height of boys = 5635 - 2265 = 3370

Mean height of 20 boys = 3370 ÷ 20 = 169 cm