Question
The average electricity consumption of a household over
a number of months was 180 units. In the next month, it consumed 300 units, raising the average by 5 units. Find the total units consumed before the last month.Solution
Let the number of months before be 'P'.
Units before = 180P
(180P + 300) / (P + 1) = 185
=> 180P + 300 = 185P + 185
=> 5P = 115 => P = 23
Total units = 180 × 23 = 4140 units
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