The average height of a group of 7 girls is 133 cm. When Gem and Lucy left the group, the average height decreased by 10 cm. What is Gem and Lucy's total height?
| |
7 girls |
5 girls |
| Number |
7 |
5 |
| Value |
133 |
123 |
| Total value |
931 |
615 |
Total number of girls after 2 girls left the group
= 7 - 2
= 5
New average height after 2 girls left the group
= 133 - 10
= 123 cm
Total height of 7 girls
= 7 x 133
= 931 cm
Total height of 5 girls
= 5 x 123
= 615 cm
Total height of Gem and Lucy
= 931 - 615
= 316 cm
Answer(s): 316 cm
