Rodger put $1,000 in a bank account that pays 5% annual simple interest. At the end of four years, how much interest has he earned and what is the balance of his account

He has earned $200 interest and the balance of his account is $1,200.

Step-by-step explanation:

Given: Principal : P = $1,000

Simple interest rate : r = 5% = 0.05

Time: t = 4 years

Simple interest =

i.e. Simple interest = $200

Balance of account = Principal + Simple interest

=  $1,000 + $200

= $1,200

Hence, he has earned $200 interest and the balance of his account is $1,200.

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.