Very-Short and Short-Answer Questions

It is given that the numbers a, 9, b, 25 form an AP.

$\therefore 9-a=b-9=25-b$

So,

$b-9=25-b$

$\Rightarrow 2 b=34$

$\Rightarrow b=17$

Also,

$9-a=b-9$

$\Rightarrow a=18-b$

$\Rightarrow a=18-17 \quad(b=17)$

$\Rightarrow a=1$

Hence, the required values of a and b are 1 and 17, respectively.