Problems need HardWork 3

Let k k be the number of positive integers that leaves a remainder of 24 when divided into 4049. Find k k .


The answer is 8.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Chew-Seong Cheong
Sep 17, 2015

We note that 4049 24 = 4025 = 5 2 × 7 1 × 2 3 1 4049-24 = 4025 = 5^\color{#D61F06}{2}\times 7^\color{#D61F06}{1} \times 23^\color{#D61F06}{1} . Therefore, the total number of factors of 4025 4025 is ( 2 + 1 ) ( 1 + 1 ) ( 1 + 1 ) = 12 (\color{#D61F06}{2}+1) (\color{#D61F06}{1}+1) (\color{#D61F06}{1}+1) = 12 and there are 4 4 factors 1 1 , 5 5 , 7 7 and 23 23 which are less than 24 24 . Therefore, the number of positive integers that leave a remainder of 24 when divided into 4049 is 12 4 = 8 12-4 = \boxed{8} .

Dev Sharma
Aug 22, 2015

4049 - 24 = 4025

so prime factors of 4025 { 5 , 5, 7, 23 }, all less than 24. (other factors: 5 5, 5 7, 5 23, 7 23, 5 5 7, 5 5 23, 5 7 23, 5 5 7*23}

Factors of 4025 that are less than 23 ( 4! / 2! ) - 4 12 - 4 8

So, the answer is 8.

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...