Probability of selecting 1 dead, 1 weak, then 1 weak = (1/588).
Given: 50 total batteries, of which 10 are dead and 5 are weak. This is represented by: 10/50 (simplifies to 1/5) and 5/50 (simplifies to 1/10).
If the batteries are being set aside, it likely means no replacement. For every battery taken out of the box, the box holds one less battery.
Probability of selecting 1 dead, 1 weak, 1 weak is written as: (10/50)*(5/49)*(4/48) = 1/588.