Question

change into passive voice
they were solving sums

Answer 1

Sums were being solved by them.

This is the passive voice of the sentence given in the que.

Answer 2

Hey mate!! WISHING YOU A VERY JOYFUL AND HAPPY NEW YEAR!! ✨✨✨❤❤

HERE'S YOUR ANSWER:

The sums were being solved by them.

Hope this helps...