The ages of Tosan and Isa differ by 6 and the product of their ages is 187. Write their ages in the form (x, y), where x > y.
-
A.
(12, 6) -
B.
(23, 17) -
C.
(17, 11) -
D.
(18, 12)
Correct Answer: Option C
Explanation
x – y = 6…….(i)
xy = 187…….(ii)
From equation (i), x(6 + y)
sub. for x in equation (ii) = y(6 + y)
= 187
y2 + 6y = 187
y2 + 6y – 187 = 0
(y + 17)(y – 11) = 0
y = -17 or y = 11
y cannot be negative, y = 11
Sub. for y in equation(i) = x – 11
= 16
x = 6 + 11
= 17
∴(x, y) = (17, 11)