Answer:A
Step-by-step explanation: In exponents,
a
1
m
=
m
√
a
Hence
x
1
2
=
2
√
x
The first one means 85 ÷ 5 = 17
The second one means 39 ÷ 3 = 13
The third one means 82 ÷ 2 = 41
The fourth one means 90 ÷ 6 = 15
The fifth one means 80 ÷ 8 = 10
86 minutes would have passed.
