The formula of the Simple Interest is:
I=PRT
P for Principle Amount ($1200)
R for Rate (5%=
= 0.05)
T for Time in years (4 years)
I = 1200 × 0.05 × 4
= $240
Add the interest to the principle amount to check the balance
$1200 + $240 = $1440
1a. 5/10 can be simplified to 1/2. (5 divided by 5 is one, 10 divided by 5 is 2.)
1b. 9/12 can be simplified to 3/4. (9 divided by 3 is 3, 12 divided by 3 is 4.)
1c. 12/18 can be simplified to 2/3. (12 divided by 6 is 2, 18 divided by 6 is 3.)
1d. 9/24 can be simplified to 3/8. (9 divided by 3 is 3, 24 divided by 3 is 8.)
1e. 27/90 can be simplified to 3/10. (27 divided by 9 is 3, 90 divided by 9 is 10.)
1f. 40/48 can be simplified to 5/6. (40 divided by 8 is 5, 48 divided by 8 is 6.)
There aren't really any instructions for this, so I'll just go ahead and find the total amount of money for both months. The first month Adriano had 200 subscribers. 5 times 200 is 1000, so Adriano received $1000 that month. The second month 40 members joined, but 10 cancelled their subscription. Taking this into account, we'll just say that 30 members joined. 30 times 5 is 150, and 150 plus 1000 is 1150. Therefore, Adriano had to have received $1150 the second month.
I'm not entirely sure what the question was to begin with, but I hope this answers it!
