I know the solution is B but I need help understanding why

Please explain where the 3/12 fraction came from in the solution for interest revenue

9000 x .1 x (3/12) = 225

also

Please explain where the 6/12 fraction came from in the solution for interest receivable

9000 x .1 x (6/12) = 450

7. On July 1, 2018, Herzog Mining lends cash and accepts a $9,000 note receivable that offers 10% interest and is due in nine months. How would Herzog record the transaction on April 1, 2019, when the borrower pays Herzog the correct amount owed? A Cash 9,675 Notes Receivable Interest Revenue B. Cash 9.675 Notes Receivable 9.000 Interest Revenue 225 Interest Receivable 450 C. Cash Notes Receivable Interest Receivable Cash 9,675 Notes Receivable A. Option A B. Option B C. Option D. Option D Interest revenue = $9,000 * 10% * 3/12 = $225. Interest receivable = $9,000 * 10% *6/12 - $450