Aasheesh can paint his doll in 20 minutes and his sister Chinki can do so in 25 minutes.

Aasheesh can paint a doll in 20 minutes, and Chinki can do the same in 25 minutes.

$\therefore$ Work done by Aasheesh in 1 minute $=\frac{1}{20}$

$\therefore$ Work done by Chinki in 1 minute $=\frac{1}{25}$

$\therefore$ Work done by them together $=\frac{1}{20}+\frac{1}{25}$

$=\frac{5+4}{100}=\frac{9}{100}$

$\therefore$ Work done by them in 5 minutes $=5 \times \frac{9}{100}=\frac{9}{20}$

Remaining work $=1-\frac{9}{20}=\frac{11}{20}$

It is given that the remaining work is done by Aasheesh.

The work done by Aasheesh in 20 minutes.

$\therefore \frac{11}{20}$ th work will be done by Aasheesh in $\left(20 \times \frac{11}{20}\right)$ minutes or 11 minutes.

Thus, the remaining work is done by Aasheesh in 11 minutes.