Here is the question I am refering to from the Prepswift quiz:
There are 45 multiples of 3 between 85 and positive integer b, inclusive. What is the largest possible value of b?
In the solution, it is stated that we have to start from 87 since 85 is not a multiple of 3. Why is that? There are several problems on this quiz where we just start from the given range, so what makes this question any different? Is it because is asking for the largest possible value of b?
Thanks!
Have you tried starting with 85? Did it end up making a difference?
I believe the answer was wrong when I started with 85. I think the reasoning though for starting from 87 is because we know there aren’t any multiples of 3 before 87 so we wouldn’t be missing any.
Makes sense, but then why would the answer be wrong if it doesn’t matter?
I think if you want to use the formula given in PrepSwift then the start and end MUST be multiples, right?
Yes, we would have to start and end from multiples of 3.