The electric company charges Tk 30 per kilowatt-hour (KWH). Rahim used 2800 KWH in April, 3200 KWH in May, and 3600 KWH in June. What was his average cost of electricity for the 3 months?

A Tk. 72

B Tk. 96

C Tk. 48

D Tk. 144

Correct Answer: Option E

For April,

Cost of electric bill = (2800 * 0.30) tk

= 840 tk

For May,

Cost of electric bill = (3200 * 0.30) tk

= 960 tk

For June,

Cost of electric bill = (3600 * 0.30) tk

= 1080 tk

Total Cost of 3 Months = (840 + 960 + 1080) tk