Sergio's internet provider charges its customers $8 per month plus 5¢ per minute of on-line usage. Sergio
received a bill from the provider covering a 2-month period and was charged a total of $46.50. How many
minutes did he spend on-line during that period? (Round to the nearest whole minute, if necessary.)

Question

Sergio's internet provider charges its customers $8 per month plus 5¢ per minute of on-line usage. Sergio
received a bill from the provider covering a 2-month period and was charged a total of $46.50. How many
minutes did he spend on-line during that period? (Round to the nearest whole minute, if necessary.)

tkhunny · Answer

What say you?

No minutes: $8
1 minute: $8 + 0.05 = $8.05
2 minutes: $8 + 0.05*2 = $8.10
...
10 minutes: $8 + 0.05*10 = $8.50
...
100 minutes: $8 + 0.05*100 = $13.00
...
How far shall we go to get $46.50?

anonymous · Answer

$8 + .05*770 = $46.50

anonymous · Answer

Would it 770 minutes? @tkhunny

tkhunny · Answer

Works for me.  Why do you doubt?  Good work.

anonymous · Answer

Just checked my teacher's answer key and it says 610 minutes. But I don't see how it could be!

tkhunny · Answer

Check it out.  8.00 + 610*0.05 = 8.00 + 30.05 = 38.05 -- Nope.

Go ahead and prove it.  No need to doubt.  :-)

anonymous · Answer

Thanks!