For simplicity take n = 6 ..
Sum of first 6 consecutive terms = 6x +15
Now say x = 2 or x = 5 each time the sum is a multiple of 9 but the sum os not even Hence we get no ..hence it is sufficient
DS
This topic has expert replies
Source: Beat The GMAT — Data Sufficiency |
-
sujaysolanki
- Master | Next Rank: 500 Posts
- Posts: 214
- Joined: Wed Nov 14, 2007 6:30 am
- Thanked: 15 times
1) For this statement we need to know that an odd number + another odd number = an even number, and an odd number + an even number = an odd number. If n = 6, that means there are 3 pairs of an odd and an even number. When we sum up each of the three pairs, we have 3 odd numbers. When we sum up the 3 odd numbers, we have an odd number.
2) I think this statement means if we take all the numbers and use them as digits to form 1 number, then that number is a multiple of 9. For example, 9, 45, 234, etc, fit the criteria. We also know for a number to be a multiple of 9, the sum of its digits must equal 9, which is an odd number.
Therefore the answer is D.
2) I think this statement means if we take all the numbers and use them as digits to form 1 number, then that number is a multiple of 9. For example, 9, 45, 234, etc, fit the criteria. We also know for a number to be a multiple of 9, the sum of its digits must equal 9, which is an odd number.
Therefore the answer is D.
Last edited by Argen on Mon Jan 07, 2008 12:42 pm, edited 1 time in total.
