Question

Your 2500 gallon pool has sprung a leak and loses 70% of its water every 10 minutes. How much water will remain in the pool after 30 minutes?

Answer 1

Total water remaining after 30 minutes is 67.5

Explanation:

Total gallon pool= 2500

If 70% of water is lost every 10 minutes, how much water will remain after 30 minutes.

First 10 minutes

70% of 2500

= 70/100 * 2500

=0.7*2500

= 1750

Total remaining after first 10 minutes = 2500-1750

=750

Second 10 minutes (20 minutes)

70% of 750

70/100 * 750

0.7 * 750

525

Total remaining after the second 10 minutes (20 minutes)

750-525

225

Third 10 minutes (30 minutes)

70% of 225

70/100 * 225

0.7 * 225

157.5

Total remaining after the third 10 minutes ( 30 minutes)

225-157.5

=67.5

Answer 2

2432.5 gallons

Explanation:

Given that the pool loses 70% of it's water every ten minutes, it means that in 30 minutes, 70% of the volume of water present would have been lost. Mathematically, in the first 10 minutes, the water lost

= 70% * 2500 gallon

= 1750 gallons

Volume of water left

= 2500 - 1750

= 750 gallons

After another 10 minutes (20 minutes in total), the water lost

= 70% * 750

= 525 gallons

Volume of water left

= 750 - 525

= 225 gallons

After another 10 minutes (30 minutes in total), the water lost

= 70% * 225

= 157.5 gallons

Volume of water left

= 225 - 157.5

= 67.5 gallons

Total volume of water lost after 30 minutes

= 2500 - 67.5

= 2432.5 gallons