The average age of a group of person going for picnic is 16 years. Twenty new persons with an average age of 15 years join the group on the spot due to which their average becomes 15.5 years. Find the number of persons initially going for picnic.  Choose the correct choice
A) 20
B) 18
C) 22
D) 19
E) None of the above
Let the number of persons, initially going for Picnic = x   ∴ Sum of their ages = 16x   Also, 16x+15×20/x+20 = 15.5   ⇒ 0.5x = 10 ⇒ x = 20 years.   20nswer 20
<result>A</result>
The average age of a group of person going for picnic is 16 years. Twenty new persons with an average age of 15 years join the group on the spot due to which their average becomes 15.5 years. Find the number of persons initially going for picnic.