To solve the bike-shop problem, let's define our variables clearly.
Let:
- \( u \) = number of unicycles
- \( b \) = number of bicycles
Next, we can set up the equations based on the information given:
- Each unicycle has 1 seat and 1 wheel.
- Each bicycle has 1 seat and 2 wheels.
From the problem, we know the following:
- The total number of seats is 18.
- The total number of wheels is 28.
Using this information, we can create two equations:
-
For the seats: \[ u + b = 18 \]
-
For the wheels: \[ u + 2b = 28 \]
Now we can solve these equations step-by-step.
Step 1: Solve for one variable using the first equation.
From the first equation: \[ u = 18 - b \]
Step 2: Substitute this expression into the second equation.
Substituting \( u \) in the second equation: \[ (18 - b) + 2b = 28 \]
Step 3: Simplify and solve for \( b \).
Simplifying the equation: \[ 18 - b + 2b = 28 \] \[ 18 + b = 28 \] \[ b = 28 - 18 \] \[ b = 10 \]
Step 4: Substitute \( b \) back into the equation for \( u \).
Now, substitute \( b = 10 \) back into the first equation: \[ u + 10 = 18 \] \[ u = 18 - 10 \] \[ u = 8 \]
Conclusion:
There are:
- \( u = 8 \) unicycles
- \( b = 10 \) bicycles
So the final answer is:
- Let \( u = 8 \) (number of unicycles)
- Let \( b = 10 \) (number of bicycles)