One-third of the sum of two numbers is 12, twice their difference is 12. Find the numbers.
A.
22 and 14
B.
20 and 16
C.
21 and 15
D.
23 and 13
Correct answer is C
Let the two numbers be x and y
\(\frac{1}{3}( x + y) = 12\)
then x + y = 36 ..........i
2( x - y) = 12
x - y = 6 ............ii
add equations i and ii
2x = 42
x = 21, put x = 21 into equation i
x + y = 36
21 + y = 36
y = 36 - 21 = 15
therefore the numbers are 21 and 15
