Difference between revisions of "1979 AHSME Problems/Problem 5"

(Created page with "== Problem 5 == Find the sum of the digits of the largest even three digit number (in base ten representation) which is not changed when its units and hundreds digits are i...")
 
m (See also)
Line 18: Line 18:
 
{{AHSME box|year=1991|num-b=4|num-a=6}}   
 
{{AHSME box|year=1991|num-b=4|num-a=6}}   
  
[[Category: Intermediate Geometry Problems]]
+
[[Category: Introductory Algebra Problems]]
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 11:50, 5 January 2017

Problem 5

Find the sum of the digits of the largest even three digit number (in base ten representation) which is not changed when its units and hundreds digits are interchanged.

$\textbf{(A) }22\qquad \textbf{(B) }23\qquad \textbf{(C) }24\qquad \textbf{(D) }25\qquad \textbf{(E) }26$

Solution

Solution by e_power_pi_times_i

Since the number doesn't change when the units and hundreds digits are switched, the number must be of the form $aba$. We want to create the largest even $3$-digit number, so $a = 8$ and $b = 9$. The sum of the digits is $8+9+8 = \boxed{\textbf{(D) } 25}$.

See also

1991 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
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
All AHSME Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png