The average height of a group of 7 girls is 133 cm. When Usha and Nora left the group, the average height decreased by 4 cm. What is Usha and Nora's total height?
|
7 girls |
5 girls |
Number |
7 |
5 |
Value |
133 |
129 |
Total value |
931 |
645 |
Total number of girls after 2 girls left the group
= 7 - 2
= 5
New average height after 2 girls left the group
= 133 - 4
= 129 cm
Total height of 7 girls
= 7 x 133
= 931 cm
Total height of 5 girls
= 5 x 129
= 645 cm
Total height of Usha and Nora
= 931 - 645
= 286 cm
Answer(s): 286 cm