The average height of a group of 6 boys is 107 cm. When Michael, Jack and Bryan joined the group, the average height increased by 4 cm. What is Michael, Jack and Bryan's total height?
| |
6 boys |
9 boys |
| Number |
6 |
9 |
| Value |
107 |
111 |
| Total value |
642 |
999 |
Total number of boys after 3 more boys joined the group
= 6 + 3
= 9
New average height after 3 more boys joined the group
= 107 + 4
= 111 cm
Total height of 6 boys
= 6 x 107
= 642 cm
Total height of 9 boys
= 9 x 111
= 999 cm
Total height of Michael, Jack and Bryan
= 999 - 642
= 357 cm
Answer(s): 357 cm
