a2+a4+…+an=30 ...(1)
a1+a3+…+an−1=24 ...(2)
(1)−(2)
(a2−a1)+(a4−a3)…(an−an−1)=6
⇒2n d=6⇒nd=12an−a1=(n−1)d=221⇒nd−d=221⇒12−221=d⇒d=23,n=8
$\begin{aligned}
& \text { Sum of odd terms }=\frac{4}{2}[2 \mathrm{a}+(4-1) 3]=24 \
& \Rightarrow \mathrm{a}=\frac{3}{2} \
& \text { A.P. } \Rightarrow \frac{3}{2}, 3, \frac{9}{2}, 6, \frac{15}{2}, 9, \frac{21}{2}, 12
\end{aligned}$
no. of integer terms =4