The average height of a group of 5 girls is 102 cm. When Xuan and Gabby joined the group, the average height increased by 9 cm. What is Xuan and Gabby's total height?
| |
5 girls |
7 girls |
| Number |
5 |
7 |
| Value |
102 |
111 |
| Total value |
510 |
777 |
Total number of girls after 2 more girls joined the group
= 5 + 2
= 7
New average height after 2 more girls joined the group
= 102 + 9
= 111 cm
Total height of 5 girls
= 5 x 102
= 510 cm
Total height of 7 girls
= 7 x 111
= 777 cm
Total height of Xuan and Gabby
= 777 - 510
= 267 cm
Answer(s): 267 cm
