2 cannons fire projectiles upwards with the same velocity. The
cannonball on the left has 4 times the mass of the cannonball on the
right. What can be correctly concluded about their trajectories?

Explanation:

Given

Two projectile is fired vertically upward

One has 4 times the mass of other

When Projectile is fired their trajectory is independent of mass of object. Also if they launched with same speed then both achieved same maximum height in same time and will hit the ground at the same moment.