SOLUTION: The ratio of the units digit to the tens digit of a two-digit number is one-half. The tens digit is two more than the units digit. Find the number.

Algebra ->  Test -> SOLUTION: The ratio of the units digit to the tens digit of a two-digit number is one-half. The tens digit is two more than the units digit. Find the number.      Log On


   



Question 1133070: The ratio of the units digit to the tens digit of a two-digit number is one-half. The tens digit is two more than the units digit. Find the number.
Found 4 solutions by MathLover1, Theo, MathTherapy, Alan3354:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

Let xy be the number. 
x is the tens digit, y is the units digit
  The ratio of the units digit to the tens digit, y%2Fx, is+1%2F2.  This gives us the proportion
y%2Fx+=+1%2F2
The tens digit is 2+more than the units digit;
x+=+y%2B2 substituting in our proportion we have
y%2F%28y%2B2%29+=+1%2F2
Cross multiply:
y%2A2+=+%28y%2B2%29%2A1
2y+=+y%2B2
Subtract y from each side:
2y+-+y+=+y%2B2-y
y+=+2
then
x+=+y%2B2
x+=+2%2B2
x+=4
so, your two digit number is:
xy+=+42%C2%A0

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
u = units digit
t = tens digit

u/t = 1/2.
t = u + 2

therefore, u/t = 1/2 becomes u/(u+2) = 1/2
multiply both sides of the equation by (u+2) to get:
u = 1/2 * (u + 2)
simplify to get:
u = 1/2 * u + 1
subtract 1/2 * u from both sides to get:
u - 1/2 * u = 1
combine like terms to get:
1/2 * u = 1
solve for u to get:
u = 2

t = u + 2 becomes t = 2 + 2 which becomes t = 4

you have t = 4 and u = 2
u/t = 1/2 becomes 2/4 = 1/2 which is true.
t = u + 2 becomes t = 2 + 2 which becomes t = 4 which is true.

solution looks good.
solution is that the tens digit is equal to 4 and the ones digit is equal to 2.
the number is 42.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
The ratio of the units digit to the tens digit of a two-digit number is one-half. The tens digit is two more than the units digit. Find the number.
Let the tens digit be T and the units digit, U
We then get: matrix%281%2C3%2C+U%2FT%2C+%22=%22%2C+1%2F2%29
T = 2U ------- Cross-multiply ------ eq (i)
Also, T = U + 2 ------ eq (ii)
2U = U + 2 ------- Substituting 2U for T in eq (ii)
2U - U = 2
U, or units digit = 2
T = 2(2) ------- Substituting 2 for U in eq (i)
T, or tens digit = 4
highlight_green%28matrix%281%2C2%2C+%22Number%3A%22%2C+42%29%29
For the "life of me," I don't know why @MATHLOVER and @THEO just love to COMPLICATE these math problems when they can be solved much, much easier
and in far less time than they make them seem. I really don't believe anyone having problems with math wants to take FOREVER to solve math problems.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The ratio of the units digit to the tens digit of a two-digit number is one-half.
---------
1/2 is not a ratio. It's a fraction.
1:2 is a ratio.