The average height of a group of 7 boys is 110 cm. When Ian, George and Ben joined the group, the average height increased by 3 cm. What is Ian, George and Ben's total height?
| |
7 boys |
10 boys |
| Number |
7 |
10 |
| Value |
110 |
113 |
| Total value |
770 |
1130 |
Total number of boys after 3 more boys joined the group
= 7 + 3
= 10
New average height after 3 more boys joined the group
= 110 + 3
= 113 cm
Total height of 7 boys
= 7 x 110
= 770 cm
Total height of 10 boys
= 10 x 113
= 1130 cm
Total height of Ian, George and Ben
= 1130 - 770
= 360 cm
Answer(s): 360 cm
