The average height of 15 girls out of a class of 30 is 152 cm. and that of the remaining girls is 156 cm. The average height of the whole class is :  Choose the correct choice:
A) 150 cms
B) 151 cms
C) 152 cms
D) 154 cms
E) 156 cms
Explanation:   Average height of the whole class =(15×152+15×156/30)=154 cms   Answer 154 cms
<result>D</result>
The average height of 15 girls out of a class of 30 is 152 cm. and that of the remaining girls is 156 cm. The average height of the whole class is :