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Guest22
 
 

How many integers between 324,700

by Guest22 Thu Sep 11, 2008 2:28 pm

How many integers between 324,700 and 458,600 have tens digit 1 and units digit 3?
(A) 10,300
(B) 10,030
(C) 1,353
(D) 1,352
(E) 1,339
Raj
 
 

Re: How many integers between 324,700

by Raj Fri Sep 12, 2008 12:43 am

458600
324700

Diff 133900

Since the last two digits have to be 13, discounting those digits, it seems to be the case that there will be 4586-3247=1339 such cases (this is true for any other combination of last two digits I think).

Is (E) the OA ? I hope I made some sense:-)
-Raj.



Guest22 Wrote:How many integers between 324,700 and 458,600 have tens digit 1 and units digit 3?
(A) 10,300
(B) 10,030
(C) 1,353
(D) 1,352
(E) 1,339
guest22
 
 

by guest22 Fri Sep 12, 2008 9:52 am

Yes. E is the OA :)
PLS XPLAIN
 
 

Hello.. I dint understand the way to resolve this problem..

by PLS XPLAIN Thu Sep 25, 2008 2:01 pm

Can you please help & explain again...??
RonPurewal
Students
 
Posts: 19744
Joined: Tue Aug 14, 2007 8:23 am
 

Re: How many integers between 324,700

by RonPurewal Tue Oct 14, 2008 4:12 am

Raj Wrote:458600
324700

Diff 133900

Since the last two digits have to be 13, discounting those digits, it seems to be the case that there will be 4586-3247=1339 such cases (this is true for any other combination of last two digits I think).

Is (E) the OA ? I hope I made some sense:-)
-Raj.



Guest22 Wrote:How many integers between 324,700 and 458,600 have tens digit 1 and units digit 3?
(A) 10,300
(B) 10,030
(C) 1,353
(D) 1,352
(E) 1,339


correct.

this happens exactly every 100th integer - no variation at all there, each "successful" integer is exactly 100 greater than the last one - and the total pool of integers under consideration is a multiple of 100, so there won't be any pattern interrupts. therefore, you can just divide the total # of integers by 100 and you're good.

if you were considering runs of integers that weren't multiples of 100, such as, say, the integers from 134,523 to 135,508, then you'd have to worry about the behavior at the boundaries.