Art of Problem Solving

2006 Cyprus MO/Lyceum/Problem 24: Difference between revisions

1=2 (talk | contribs)
New page: ==Problem== {{empty}} ==Solution== {{solution}} ==See also== {{CYMO box|year=2006|l=Lyceum|num-b=23|num-a=25}}
 
solution
Line 1: Line 1:
==Problem==
==Problem==
{{empty}}
The number of divisors of the number <math>2006</math> is
 
A. <math>3</math>
 
B. <math>4</math>
 
C. <math>8</math>
 
D. <math>5</math>
 
E. <math>6</math>


==Solution==
==Solution==
{{solution}}
<math>2006 = 2 \cdot 17 \cdot 59</math>. A number has <math>(m_1 + 2)(m_2 + 1) \cdots (m_n + 1)</math> divisors, where <math>N = p_1^{m_1} \cdots p_n^{m_n}</math>, with prime <math>p_i</math>. Thus <math>2006</math> has <math>(1+1)^3 = 8\ \mathrm{(C)}</math> divisors.


==See also==
==See also==
{{CYMO box|year=2006|l=Lyceum|num-b=23|num-a=25}}
{{CYMO box|year=2006|l=Lyceum|num-b=23|num-a=25}}
[[Category:Introductory Algebra Problems]]

Revision as of 17:26, 15 October 2007

Problem

The number of divisors of the number $2006$ is

A. $3$

B. $4$

C. $8$

D. $5$

E. $6$

Solution

$2006 = 2 \cdot 17 \cdot 59$. A number has $(m_1 + 2)(m_2 + 1) \cdots (m_n + 1)$ divisors, where $N = p_1^{m_1} \cdots p_n^{m_n}$, with prime $p_i$. Thus $2006$ has $(1+1)^3 = 8\ \mathrm{(C)}$ divisors.

See also

2006 Cyprus MO, Lyceum (Problems)
Preceded by
Problem 23
Followed by
Problem 25
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30