Answer:
a) 293 units
b) 5795p
Explanation:
First, determine how many units used
Take the new reading and subtract the old reading
6538 - 6245
293 units
The first 200 is at 22p
200 * 22 p =4400p
293 -200 = 93 units at the remaining unit price.
93 * 15 p =1395p
Add the two totals together
4400p + 1395p =5795p