A father and his son wants to play on a seesaw we're on the seesaw should each of them sit to balance the torque

Answer 1

place them so their mass*distance products match.
m1 * d1 = m2 * d2

and that's "where," not we're ...

Answer 2

answers for Applications Of Torque Quick Check:
1. C
2. D
3. D
4. C