Question

If 11 AM's are inserted between 28 and 10 then the middle term in the series is.?​

Answer 1

Answer:

LetA1,A2.........A4............ be the A.M inserted between 28 and 10

then

28,A1,A2.........A4,10  is an AP with a=28, 

a13=10

⇒a+12d=10

⇒28+12d=10

⇒12d=−18

⇒d=12−18=2−3

Middle form=213+1=7thterm

=a7

=a+6d=28+6×2−3=19