Answer
At end of the second month you earned $3.36 as interest.
Step by step explanation
First month investment = $75
Rate of interest = 3.75% APR = 3.75/100 = 0.0375
Monthly interest = 0.0375/12 = 0.003125
At end of the first month interest amount = 0.003125 *75 = 0.234375
= $0.23
Amount after 1st month = 75 + 0.23 = $75.23
Second month invested $1000/
So the principle amount at beginning of the second month = $1000 + $75.23
P = $1075.23
Second month interest = 1075.23*0.003125 = $3.36
Therefore, at end of the second month you earned $3.36 as interest.
Thank you. :)