Garrett plans to attend the Scott County Fair and is trying to decide what would be a better deal. He can pay $30 for unlimited rides, or he can pay $17 for admission plus $1 per ride. If Garrett goes on a certain number of rides, the two options wind up costing him the same amount. How many rides is that? What is that cost? ​

Complete Question

When loaded with iron rods a lorry has mass of 12000kg. if the mass of iron rods is three times that of the empty lorry, find the mass of iron.

3000kg

Step-by-step explanation:

Let us represent

Mass of lorry = x

Mass of iron rods = y

x + y = 12000kg Equation 1

x = 12000kg - y

We are told that:

If the mass of iron rods is three times that of the empty lorry, find the mass of iron.

x = 3y

We substitute 3y for x in Equation 1

x = 12000kg - y

3y = 12000kg - y

Collect like terms

3y + y = 12000kg

4y = 12000kg

Divide both sides by 4

y = 12000kg/4

y = 3000kg

Note that:

Mass of iron rods = y

Hence, Mass of iron rods = 3000kg