Answer:
F = 48 [N]
Step-by-step explanation:
To solve this problem we must use Newton's third law, which tells us that the sum of forces on a body must be equal to zero, that is, the body is in static equilibrium or in equilibrium.
ΣF = 0
24 + 24 - F = 0
F = 24 + 24
F = 48 [N]
Note: Jeff's force should be equal to the sum of Sally and Misha's forces, but in the opposite direction.