The average height of 50 pupils in a class is 160 cm. Five of them whose height is 146 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 choices: A) 287 cm B) 151 cm C) 276 cm D) 287 cm E) 161 cm
Total height = 160 * 50= 
<gadget id="calculator">160 * 50</gadget>
<output>8_000</output>
8000 cm.   New average= [8000 - 5 * 146 + 5 * 156 ] / 50   = 161 cm.   Answer:161 cm
<result>E</result>
The average height of 50 pupils in a class is 160 cm. Five of them whose height is 146 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 ?