The average height of a group of 9 girls is 117 cm. When Lynn and Irene left the group, the average height decreased by 11 cm. What is Lynn and Irene's total height?
| |
9 girls |
7 girls |
| Number |
9 |
7 |
| Value |
117 |
106 |
| Total value |
1053 |
742 |
Total number of girls after 2 girls left the group
= 9 - 2
= 7
New average height after 2 girls left the group
= 117 - 11
= 106 cm
Total height of 9 girls
= 9 x 117
= 1053 cm
Total height of 7 girls
= 7 x 106
= 742 cm
Total height of Lynn and Irene
= 1053 - 742
= 311 cm
Answer(s): 311 cm
