Answer:
1) 2.71%
2) $38.32
Step-by-step explanation:
Opening balance = $1220
Balance after 10 days (after expense) = $1690
Balance after 10 days(after payment) = $1340
APR = 33%
1) Periodic interest rate = APR × 
= 33%× 30/365
= 2.71%
2) Interest charged for first 10 days = 
= $11.02
Interst charged for the next 10 days = 
= $15.2
Interest charged for the next 10 days = 
= $12.10
Total interest for 30 days = 11.02+15.2+12.10
= $38.32
Answer:
The diameter of the model is 14.4 inches.
Step-by-step explanation:
The Diameter of the moon = 2,160 miles
The scale on the model represents 1 in = 150 miles
Let the model represents k inches in 2,160 miles.
So, by the Ratio of Proportionality:

⇒
or, k = 14.4 inches
⇒On the scale 2160 miles is represented as 14.4 inches
Hence the diameter of the model is 14.4 inches.
40 mph would be 120 miles in 3 hours (120/40)
80 mph is 120 miles in 1.5 hours(120/80)
3 - 1.5 = 1.5, not 3 hrs
Change the speed to 20 mph( 1/2 the speed) to double the hours.
20 mph = 6 hours(120/20)
40 mph = 3 hrs(120/40)
6 - 3 = 3 hours difference
The slope of the line is positive 1