Answer and Explanation:
The computation is shown below;
But before reaching to the final answers, first do the following calculations
Cash collected $108000
Add	Services performed in 2017(not collected) $36000
less	Services performed in 2016(collected in 2017) $25000
Revenue for 2017	$119,000
Cash paid in 2017	$72,000
Add	Expense incurred not yet paid for 2017 $42000
Less Expense paid for 2016	-$30000
Expense for 2016 $84000 
Now 
a. Cash basis  
Revenue $108000
Less Expenses -$72,000
Net income $36000
b. Accrual basis  
Revenue for 2017	$119,000
Less Expenses for 2017 $84,000
Net income $35,000