Final answer:
Sarah bought 3 first class tickets.
Step-by-step explanation:
To find the number of first class tickets Sarah bought, we can set up an equation based on the given information. Let x be the number of coach tickets and y be the number of first class tickets. We know that Sarah bought a total of 10 tickets, so x + y = 10. Additionally, we know that each coach ticket costs $170 and each first class ticket costs $970, and Sarah used her total budget of $4100. This can be represented by the equation 170x + 970y = 4100.
To solve this system of equations, we can use substitution or elimination. Let's solve it using elimination:
- Multiply the first equation by 170 to make the coefficients of x the same: 170x + 170y = 1700.
- Subtract the second equation from the first equation: (170x + 170y) - (170x + 970y) = 1700 - 4100.
- Simplify the equation: -800y = -2400.
- Divide both sides of the equation by -800: y = 3.
Therefore, Sarah bought 3 first class tickets.