The average height of a group of 9 boys is 150 cm. When Justin, Tom and Zeph left the group, the average height decreased by 5 cm. What is Justin, Tom and Zeph's total height?
| |
9 boys |
6 boys |
| Number |
9 |
6 |
| Value |
150 |
145 |
| Total value |
1350 |
870 |
Total number of boys after 3 boys left the group
= 9 - 3
= 6
New average height after 3 boys left the group
= 150 - 5
= 145 cm
Total height of 9 boys
= 9 x 150
= 1350 cm
Total height of 6 boys
= 6 x 145
= 870 cm
Total height of Justin, Tom and Zeph
= 1350 - 870
= 480 cm
Answer(s): 480 cm
