The average age of a group of 12 students is 20years. If 4 more students join the group, the average age increases by 1 year. The average age of the new students is
24
26
23
22
Explanation:
Total age of 12 students=12 $\times$ 20=240
Total age of 4 students =4x (assuming the average age of 4 students)
Hence the equation=240+4x=16 $\times$ 21=336
solving the equation we get x=24
So, average age of the new students =24.