Answer:
6 minutes
Step-by-step explanation:
Machine A produces x boxes in 10 minutes
In one minute, the machine produces x/10 boxes
Machine B produces 2x boxes in 5 minutes
In one minute, the machine produces 2x/5 boxes
Therefore in one minutes, both boxes working together will produce
= 2x/5 + x/10
=5x/10
=x/2 boxes
To produce 3x boxes, the time required
= 3x/(x/2)
= 3 × 2
= 6
It take machines A and B, working simultaneously at their respective constant rates, to produce 3x boxes in 6 minutes