The average height of 50 pupils in a class is 150 cm. Five of them whose height is 142 cm, leave the class and five others whose average height is 156 cm, join. The new average height of the pupils of the class (in cm) is ?
Choose the correct choice from the following.
A) 287 cm	B) 151 cm	C) 151.4 cm	D) 287 cm	E) 297 cm
Total height = 150 * 50= 
<gadget id="calculator">150 * 50</gadget>
<output>7_500</output>
7500 cm.   New average= [7500 - 5 * 142 + 5 * 156 ] / 50   = 151.4 cm.   Answer:151.4 cm
<result>C</result>
The average height of 50 pupils in a class is 150 cm. Five of them whose height is 142 cm, leave the class and five others whose average height is 156 cm, join. The new average height of the pupils of the class (in cm) is ?