WILL REWARD 10 POINTS A.S.A.P
2007-11-29 12:39:07 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
The number "XY" is properly written 10x + y. The product of its digits is xy. So 10x + y = 3xy. In that case, y = 10x / (3x-1). An integer that meets this is x = 2, when y = 20/5 = 4.
Yes, 24 is the answer.
LATER
Yes, 15 is also correct, but I cheated by looking at another answer. : (
2007-11-29 12:52:02 · answer #1 · answered by anobium625 6 · 0⤊ 0⤋
10x + y = the two-digit number
10x + y = 3xy
10x = 3xy - y
10x = y(3x-1)
10x/(3x-1) = y
Need single digit answers
20/(6-1) = 4
24 is the number
10/(3-1) = y = 5
15 is the number
30/(9-1) = y 30/8 is not a whole number
40/(12-1) 40/11 is not a whole number
50/(15-1) 50/14 is not
60/(18-1) 60/17 is not
70/(21-1) 70/20 is not
80/(24-1) 80/23 is not
90/(27-1) 90/26 is not
The only two-digit answers are 15 and 24.
2007-11-29 20:46:40 · answer #2 · answered by Steve A 7 · 0⤊ 0⤋
15.
(1x5)x3 = 15.
2007-11-29 20:45:32 · answer #3 · answered by Will P 2 · 0⤊ 1⤋