How do I do this shopping cart exercise?

Automobile

DBS's Automotive performs the following routine maintenance services:

Oil changes €50
Lube Job €20
Radiator flush €60
Transmission flush €100
Inspection €10
Muffler replacement €200
Tire Rotation €30

DBS also performs other nonroutine services and charges for parts and labour (€30 per hour). Create an Application that displays the total for a customer's visit to DBS.

The application should have the following value-returning methods

oilLubeCharges - returns the total charge for an oil change and / or a lube job, if any.

flushCharges - returns the total charges for a radiator flush and/ or a transmission flush, if any

miscCharges - returns the total charges for an inspection, muffler replacement, and / or tire rotation it any.

otherCharges - returns the total charges for other services(parts and labour), if any.

taxCharges - returns the amount of sales tax if any. Sales tax is 10% and is charged only on parts. if the customer purchases services only, no sales tax is charged.

totalCharges - returns the total charges.

The application should have the following void methods, called when the user clicks the clear button.

clearOilLube- Clears the check boxes for the oil change and lube change

clearFlushes - Clears the check boxes for radiator flush and transmission flush.
clearMisc - Clears the check boxes for instection, muffler replacement and tire rotation

clearOther - Clears the text boxes for parts and labour

clearFees - Clears the labels that display the labels in the section marked summary

Demonstrate how you solved this problem.

Automobile

DBS's Automotive performs the following routine maintenance services:

Oil changes €50
Lube Job €20
Radiator flush €60
Transmission flush €100
Inspection €10
Muffler replacement €200
Tire Rotation €30

DBS also performs other nonroutine services and charges for parts and labour (€30 per hour). Create an Application that displays the total for a customer's visit to DBS.

The application should have the following value-returning methods

oilLubeCharges - returns the total charge for an oil change and / or a lube job, if any.

flushCharges - returns the total charges for a radiator flush and/ or a transmission flush, if any

miscCharges - returns the total charges for an inspection, muffler replacement, and / or tire rotation it any.

otherCharges - returns the total charges for other services(parts and labour), if any.

taxCharges - returns the amount of sales tax if any. Sales tax is 10% and is charged only on parts. if the customer purchases services only, no sales tax is charged.

totalCharges - returns the total charges.

The application should have the following void methods, called when the user clicks the clear button.

clearOilLube- Clears the check boxes for the oil change and lube change

clearFlushes - Clears the check boxes for radiator flush and transmission flush.
clearMisc - Clears the check boxes for instection, muffler replacement and tire rotation

clearOther - Clears the text boxes for parts and labour

clearFees - Clears the labels that display the labels in the section marked summary

Demonstrate how you solved this problem.

Same problem, just greasier.