The average height of a certain number of persons in a group is 155.5 cm. Later on, 4 persons of height 154.6 cm, 158.4 cm, 152.2 cm and 153.8 cm leave the group. As a result the average height of the remaining persons increases by 0.15 cm. What was the number of persons initially in the group?

The average height of a certain number of persons in a group is 155.5

1.	The average height of a certain number of persons in a group is 155.5 cm. Later on, 4 persons of height 154.6 cm, 158.4 cm, 152.2 cm and 153.8 cm leave the group. As a result the average height of the remaining persons increases by 0.15 cm. What was the number of persons initially in the group?
A.	18
B.	20
C.	22
D.	24
Answer» E.