Back squats should be at the same weight – about 75% of your 1RM. Warm up to the weight and then go at evenly spaced intervals: 0:00, 2:30, 5:00, 7:30, 10:00.
If 100 double unders seems impossible, scale to 50. If that seems like too much, do 100 single unders. Score is rounds + reps.

Strength

Back Squat

3×5

Conditioning

AMRAP in 12 min:
100 double unders
50 wall balls, 20/14#
25 power snatches, 95/65#