kdatt1991 wrote:
Bunuel wrote:
Which of the following is divisible by the first nine positive integer multiples of 17?
(i) 14,280
(ii) 85,689
(iii) 368,420
A. none
B. iii only
C. i and ii only
D. ii and iii only
E. i, ii, and iii
Kudos for a correct solution.
Seem's like a tricky question but I hope that I have been able to crack it. Here's my solution:
I think that the first 9 positive integers multiples of 17; which are (17)*1 + (17)*2...... + (17)*9 can be written as 17*(1 + 2..... + 9). This value can be simplified to 17*(45). Therefore the options (i), (ii) and (iii) need to be divisible by all the prime factors of (17)*(45) which can be broken down into (17)*(5)*(3)*(3). Using the factors 9 and 5. we can deduce (using divisibility rules) that option (ii) is not divisible by 5, and option's (i) and (iii) are not divisible by 9. Thus it seems like none of the answer choices are divisible by the the first 9 positive integer multiples of 17.
I think the answer is A.
Please consider giving me kudos, if you felt this post was helpful. Thanks.
hi kdatt,
although the ans is correct, you have misunderstood the question because in some other values your answer would have been wrong..
the Q asks to check div by each of the first nine multiple integers of 17..
this means the value should be div by 17*1,17*2,17*3.....and 17*9..
it translates into the value to be div by each of 5,7,8,9 and 17....
but if we look at 17*45.. it means only by 5,9 and 17...
i hope it is clear...
Thanks for pointing that out to me. Seems like I need to practise on reading the questions more carefully!