Question

There are 20 students with an average height of 105 cms in a class. Then 10 students with an average height of 120 cms join the class. What will be the average height of the class now? ( A ) 100 ( B ) 130 ( C ) 120 ( D ) 110

Answer 1

Answer:

110

Step-by-step explanation:

average height of 20 students = 105

so total height = 20 ×105

=2100

average height of 10 students = 120

total height = 1200

so let us add both the total heights

total height of 30 students = 1200 + 2100

=3300

average height of 30 students = 3300/30

=110 (new)