Final answer:
The driver's tip is $1.45.
Step-by-step explanation:
The taxi cost $2.25 for the first mile plus $0.15 for each additional tenth of a mile. To find the cost of a 5.2-mile trip, we need to calculate the cost for the first mile and the cost for the additional 4.2 miles.
Cost for the first mile = $2.25
Cost for the additional 4.2 miles = $0.15 * 42 = $6.30
Total cost for the 5.2-mile trip = Cost for the first mile + Cost for the additional 4.2 miles = $2.25 + $6.30 = $8.55
Eric paid $10 and told the driver to keep the change as a tip. So, the driver's tip is $10 - $8.55 = $1.45.