The average height of a group of 50 students is 175 cm. If another group of 40 students with average height of 180 cm is included, what is the average (in cm, to the nearest cm) of the combined group?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 177.
Total height of first group = 50 × 175 = 8750 cm
Total height of second group = 40 × 180 = 7200 cm
Combined total height = 8750 + 7200 = 15,950 cm
Combined number of students = 50 + 40 = 90
Average height = 15,950 ÷ 90 = 177.22 cm ≈ 177 cm