Class 11

Math

Algebra

Sequences and Series

If eleven A.M.'s are inserted between $28$ and $10$, then find the number of integral A.M.'s.

Hence every even A.M. would be integral as it would be of the form

$10+2r×23 $ where $r$ is an integer

$=10+3r$

$=13,16,19,22,25$

Hence, $5$ integral A.M.'s.