Answer:
57.1428 minutes
Explanation:
Power : Time
100 : 20
35 : x
if POWER increase then TIME decrease, it means both are inversely proportional to each other
x/20 = 100/35
x = (100/35) * 20
x = 400 / 7
x = 57.1428
where x is basically the time in minutes, So time = 57.1428 minutes