Answer:
B) 45 days
Step-by-step explanation:
You want to know how long it takes to complete 15 deposits at the rate of one every 3 days.
Time and Rate
The time is found by multiplying the number by the rate of completion:
(15 deposits) × (3 days/deposit) = 45 days . . . . . . matches choice B
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Additional comment
The time that elapses between the first deposit and the last is 42 days.
