Answer :
Amy = n
Chris = n + 18
Mean = 1/2 (Amy + Chris)
45 = 1/2 (n + n + 18)
45 = 1/2 (2n + 18)
45 = n + 9
36 = n
Amy = 36
Chris = 54
Chris = n + 18
Mean = 1/2 (Amy + Chris)
45 = 1/2 (n + n + 18)
45 = 1/2 (2n + 18)
45 = n + 9
36 = n
Amy = 36
Chris = 54