Question

find 'p' if 10,p,-2 are in an arithematic progression

Answer 1

if they are in a.p then
a2-a1=a3-a2
p-10=-2-p
p+p=10-2
2p=8
p=8/2
p=4

Answer 2

a=10

a+2d=-2

10+2d=-2

2d=-12

d=-6

10-6=4