Answer: You and your friend used 66.7 megabytes.
Explanation:
Hi, to answer this question we have to write an equation.
Your cell phone company:
y = 10 + 0.10 m
Where:
y: total cost
m = number of megabytes
Your friend's company:
y = 0.25m
If both paid the same, it means that
y = y
And
10 + 0.10m = 0.25m
Solving for m:
10= 0.25m-0.10m
10= 0.15m
10/0.15=m
66.7 =m
You and your friend used 66.7 megabytes.