The product of two digits equals eight in a two-digit number. The digits are flipped when 18 is added to the number. This is the number:
A. 18
B. 24
C. 42
D. 81
Answer:B
The product of two digits equals eight in a two-digit number. The digits are flipped when 18 is added to the number. This is the number:
A. 18 B. 24 C. 42 D. 81
Explanation: Let x and 8/x be the tens and unit digits, respectively.Then 10x + 8/x + 18 = 10 x 8/x + x = 10 x 8/x + x80 + x2 = 10x,2 + 8 + 18x,0 = 9x2 + 18x - 72,0 = x2 + 2x - 8,0 = (x + 4)(x - 2)x equals 2.