The average height of a group of 5 girls is 100 cm. When Penelope and Shannon joined the group, the average height increased by 10 cm. What is Penelope and Shannon's total height?
| |
5 girls |
7 girls |
| Number |
5 |
7 |
| Value |
100 |
110 |
| Total value |
500 |
770 |
Total number of girls after 2 more girls joined the group
= 5 + 2
= 7
New average height after 2 more girls joined the group
= 100 + 10
= 110 cm
Total height of 5 girls
= 5 x 100
= 500 cm
Total height of 7 girls
= 7 x 110
= 770 cm
Total height of Penelope and Shannon
= 770 - 500
= 270 cm
Answer(s): 270 cm
