Step-by-step explanation
Let the number of people with coach tickets be x and the number of people with first class tickets be y. Since the trip goers contained a total of 18 people we will have;
A coach ticket cost $170 dollars and the first class tickets cost $1010. Also, Sarah spent a total of $10620 to buy the tickets. This would give us;
We will now solve the equation simultaneously.
We will substiuite y =9 in x=18-y. Therefore;
Answer: From the above, Sarah bought 9 coach tickets and 9 first-class tickets.