Question

En un estacionamiento hay 55 vehículos entre coches y motos. Si el total de ruedas es de 170. Cuantos coches y cuantas motos hay?

Answer 1

Let
`x` be the number of cars (coches) and
`y` the number of motorbikes (motos).
We know that sum of cars and motorbikes is 55, so:

`x+y=55` equation (1)
We can infer that the a car has 4 wheels and a motorbike has 2 wheels.Since the total number of wheels is 170, the sum of the car's wheels and the motorbike's wheels is 170:

`4x+2y=170` equation (2)

Solving for
`x` in equation (1):

`x+y=55`

`x=55-y` equation (3)

Replacing equation (3) in equation (2):

`4x+2y=170`

`4(55-y)+2y=170`

`220-4y+2y=170`

`-2y=-50`

`y= (-50)/(-2)`

`y=25` equation (4)

Replacing equation (4) in equation (3):

`x=55-y`

`x=55-25`

`x=30`

We can conclude that there are 30 cars and 25 motorbikes in the parking lot.
Podemos concluir que hay 30 coches y 25 motos en el estacionamiento.