Four numbers are in A.P. If their sum is 20 and the sum of their squares is 120, then the middle terms are
4,6
Let the numbers are a−3d,a−d,a+d,a+3d
Given: a−3d+a—d+a+d+a+3d=20
4a=20
a=5 and
(a−3d)2+(a−d)2+(a+3d)2+(a+3d)2=120
(4)a2+20d2=120
(4)52+20d2=120
d2=1
d=+1 or−1
Hence numbers are 2,4,6,and 8