This is a question from Quant Mountain (Group 1 (Arithmetic)).
In the solution, the number of multiples of 3 from 1 to 500 is rounded down to 166. That gets us to a solution of 41,583, but if I do not round it, the solution is 41,750. If it is one of those enter the answer questions, the difference matters. Hence, my question is, when to round and when to not round, is their a GRE rule you’re aware of?
The question will indicate if you need to round.
In this instance, the question did not mention that. If it does not say anything, what should we default to?
Wait, what exactly are you rounding for?
I wasn’t rounding, that’s why I got a different answer from the one provided in the Mountain.
Please see the screenshot.
Oh that. Sorry I misunderstood earlier.
In this case, you must round down since 500 is not a multiple of 3, so the problem can be rewritten as “find the sum of all multiples of 3 from 3 to 498”.
No problem, but this reworded question still gives me a different answer:
Step 1: ((498-3)+1)/3 = 165.33
Steps 2 and 3: Remain Unchanged
Step 4: (165/2) * 501 = 41,416
You’re doing
Can you see the mistake here?
((498-3)/3)+1 is correct then?
If yes, thank you for confirming, in advance!
Thanks for sharing how we can change the question too!
Indeed.
