Question

The mean of four consecutive even five numbers is 15

Answer 1

lets take 
no.1 as x
no.2 as x+2
no.3 as x+4
no. 4 as x+6

so, x+x+2+x+4+x+6/4=15

x+x+2+x+4+x+6= 4*15
x+x+2+x+4+x+6=60
4x+12=60
4x=60-12
4x=48
x=48/4
x=12
x+2=14
x+4=16
x+6=16
verifying
12+14+16+18/4
.=60/4
=15

hope this helps!!!