The average height of a group of 5 girls is 142 cm. When Hazel and Irene joined the group, the average height increased by 4 cm. What is Hazel and Irene's total height?
| |
5 girls |
7 girls |
| Number |
5 |
7 |
| Value |
142 |
146 |
| Total value |
710 |
1022 |
Total number of girls after 2 more girls joined the group
= 5 + 2
= 7
New average height after 2 more girls joined the group
= 142 + 4
= 146 cm
Total height of 5 girls
= 5 x 142
= 710 cm
Total height of 7 girls
= 7 x 146
= 1022 cm
Total height of Hazel and Irene
= 1022 - 710
= 312 cm
Answer(s): 312 cm
