The table shows the rates charged for the use of electricity in a country.
- Charlie and his family used 30 units of electricity in March. How much did they pay for the usage of electricity in March?
- Yen and her family paid $148.70 for the usage of electricity in April. How many units of electricity did they use in April?
(a)
Amount that Charlie and his family paid for the usage of electricity
= 30 x 0.91
= $27.30
(b)
Amount that Yen and her family paid for first 40 units of electricity
= 40 x 0.91
= $36.40
Amount that Yen and her family paid for next 40 units of electricity
= 40 x 1.21
= $48.40
Amount that Yen and her family paid for the remaining units of electricity
= 148.70 - 36.40 - 48.40
= $63.90
Remaining units of electricity that Yen and her family used
= 63.90 ÷ 2.13
= 30
Total number of units of electricity that Yen and her family used
= 40 + 40 + 30
= 110
Answer(s): (a) $27.30; (b) 110
