SOLUTION: Hi
The average usage of water is 4000 litres per month. During the months of May June and July the usage is 4500 litres per month. What should the average usage of water be for t
Question 1209708: Hi
The average usage of water is 4000 litres per month. During the months of May June and July the usage is 4500 litres per month. What should the average usage of water be for the rest of the months so that the total consumption for the year is the same.
Found 4 solutions by CPhill, ikleyn, greenestamps, math_tutor2020:Answer by CPhill(1987) (Show Source): You can put this solution on YOUR website! Here's how to calculate the average water usage for the remaining months:
1. **Calculate total water usage for May, June, and July:**
4500 liters/month * 3 months = 13500 liters
2. **Calculate the expected total water usage for the year:**
4000 liters/month * 12 months = 48000 liters
3. **Calculate the remaining water needed for the year:**
48000 liters - 13500 liters = 34500 liters
4. **Calculate the number of remaining months:**
12 months - 3 months = 9 months
5. **Calculate the average water usage for the remaining months:**
34500 liters / 9 months = 3833.33 liters/month (approximately)
So, the average water usage for the rest of the months should be approximately 3833.33 liters per month to maintain the same total consumption for the year.
It can be easily solved in one line
the average usage of water for the rest of the months = = 3833.33 liters per month.
The structure of this formula makes its meaning self-obvious,
so the formula is SELF-EXPLANATORY.
In the three months of May, June, and July, water usage was 4500-4000 = 500 litres over the average each month making a total of 3*500 = 1500 litres over the average.
For the overall average for the whole year to be 4000 litres per month, the total consumption in the other 9 months must be 1500 litres under the average.
1500 litres under the average, distributed evenly over the 9 months, means monthly consumption is 1500/9 = 500/3 = 166 2/3 liters under the monthly average of 4000 litres.
Over the course of those 12-3 = 9 months, x liters per month are used.
So 9x is the amount used over those months.
3*4500 = the amount of water used over May June and July combined.
9x+3*4500 = total amount of water used over the 12 months
(9x+3*4500)/12 = average water usage per month
(9x+3*4500)/12 = 4000
9x+3*4500 = 4000*12
9x = 4000*12-3*4500
9x = 34500
x = 34500/9
x = 11500/3
x = 3833.333333...
The 3's go on forever in that decimal value.
The months other than May June July should use on average roughly 3833.333 liters of water per month.