The table shows the parking fees at a car park.

Time	Charges
First 1 hour or less	$2.50
Every additional 30 minutes or part thereof	$1.80
Overnight parking from 10 p.m. to 6:30 a.m.	$5

1. David parked his car at the carpark at 10.00 a.m. for 1 hour and 33 minutes. How much did he have to pay?
2. Wendy parked her car at the car park from 7:40 p.m. on Monday to 10 a.m. on Tuesday. Find the amount of parking fee that she had to pay.

(a)
Amount that David had to pay for 1 hour and 33 minutes
= 2.50 + 1.80 + 1.80
= $6.10

(b)
1 h = 60 min

From 7:40 p.m. to 8:40 p.m.: 1 h
Amount that Wendy had to pay from 7:40 p.m. to 8:40 p.m = $2.50

From 8:40 p.m. to 10:00 p.m.: 1 h 20 min

1 h 20 min = 1 x 60 + 20 = 80 min

Number of sets of additional 30 minutes in 1 h 20 min
= 80 ÷ 30
= 2 r 20

Number of sets of additional 30 minutes that Wendy had to pay for 
= 2 + 1
= 3

Amount that Wendy had to pay for all the additional 30 minutes or part thereof for 1 h 20 min
= 3 x 1.80
= $5.40

From 10:00 p.m. to 6.30. a.m. 
Amount that Wendy had to pay from 10:00 to 6.30 a.m. = $5

From 6.30 a.m. to 10 a.m.: 3 h 30 min

3 h 30 min = 3 x 60 + 30 = 210 min

Number of sets of additional 30 minutes in 3 h 30 min
= 210 ÷ 30
= 7

Amount that Wendy had to pay for all the additional 30 minutes or part thereof for 3 h 30 min
= 7 x 1.80
= $12.60

Total amount that Wendy had to pay
= 2.50 + 5.40 + 5 + 12.60
= $25.50

Answer(s): (a) $6.10; (b) $25.50