The table shows the rates charged for the use of utility in a country.
- Ben and his family used 25 units of utility in May. How much did they pay for the usage of utility in May?
- Cathy and her family paid $143.35 for the usage of utility in June. How many units of utility did they use in June?
(a)
Amount that Ben and his family paid for the usage of utility
= 25 x 0.78
= $19.50
(b)
Amount that Cathy and her family paid for first 40 units of utility
= 40 x 0.78
= $31.20
Amount that Cathy and her family paid for next 40 units of utility
= 40 x 1.51
= $60.40
Amount that Cathy and her family paid for the remaining units of utility
= 143.35 - 31.20 - 60.40
= $51.75
Remaining units of utility that Cathy and her family used
= 51.75 ÷ 2.07
= 25
Total number of units of utility that Cathy and her family used
= 40 + 40 + 25
= 105
Answer(s): (a) $19.50; (b) 105