The table shows the rates charged for the use of electricity in a country.

1. Reggie and his family used 25 units of electricity in January. How much did they pay for the usage of electricity in January?
2. Xandra and her family paid $162.45 for the usage of electricity in February. How many units of electricity did they use in February?

(a)
Amount that Reggie and his family paid for the usage of electricity
= 25 x 0.97
= $24.25

(b)
Amount that Xandra and her family paid for first 30 units of electricity
= 30 x 0.97
= $29.10

Amount that Xandra and her family paid for next 30 units of electricity
= 30 x 1.28
= $38.40

Amount that Xandra and her family paid for the remaining units of electricity
= 162.45 - 29.10 - 38.40
= $94.95

Remaining units of electricity that Xandra and her family used
= 94.95 ÷ 2.11
= 45

Total number of units of electricity that Xandra and her family used
= 30 + 30 + 45
= 105

Answer(s): (a) $24.25; (b) 105