The table shows the rates charged for the use of utility in a country.
- Julian and his family used 15 units of utility in May. How much did they pay for the usage of utility in May?
- Risa and her family paid $99.90 for the usage of utility in June. How many units of utility did they use in June?
(a)
Amount that Julian and his family paid for the usage of utility
= 15 x 0.77
= $11.55
(b)
Amount that Risa and her family paid for first 30 units of utility
= 30 x 0.77
= $23.10
Amount that Risa and her family paid for next 30 units of utility
= 30 x 1.39
= $41.70
Amount that Risa and her family paid for the remaining units of utility
= 99.90 - 23.10 - 41.70
= $35.10
Remaining units of utility that Risa and her family used
= 35.10 ÷ 2.34
= 15
Total number of units of utility that Risa and her family used
= 30 + 30 + 15
= 75
Answer(s): (a) $11.55; (b) 75