MathDB
Product & Sum of Digits of an Integer

Source:

January 7, 2007
algebra

Problem Statement

Let P(n) P(n) and S(n) S(n) denote the product and the sum, respectively, of the digits of the integer n n. For example, P(23) \equal{} 6 and S(23) \equal{} 5. Suppose N N is a two-digit number such that N \equal{} P(N) \plus{} S(N). What is the units digit of N N? <spanclass=latexbold>(A)</span>2<spanclass=latexbold>(B)</span>3<spanclass=latexbold>(C)</span>6<spanclass=latexbold>(D)</span>8<spanclass=latexbold>(E)</span>9 <span class='latex-bold'>(A) </span>2\qquad<span class='latex-bold'>(B) </span>3\qquad<span class='latex-bold'>(C) </span>6\qquad<span class='latex-bold'>(D) </span>8\qquad<span class='latex-bold'>(E) </span>9