Ritter Corporation$$s accountants prepared the following financial statements for year$-$end $2021$: $($Do not round intermediate calculations.$)$

RITTER CORPORATION

Income Statement

$2021$

Revenue $ $781$

Expenses $539$

Depreciation $94$

Net income $ $148$

Dividends $ $115$

RITTER CORPORATION

Balance Sheet

December $31$

$20202021$

Assets

Cash $ $65$ $ $87$

Other current assets $177195$

Net fixed assets $400420$

Total assets $ $642$ $ $702$

Liabilities and Equity

Accounts payable $ $131$ $ $149$

Long$-$term debt $157166$

Stockholders$$ equity $354387$

Total liabilities and equity $ $642$ $ $702$

a$.$ What is the change in cash during $2021?$

b$.$ Determine the change in net working capital in $2021.$

c$.$ Determine the cash flow generated by the firm$$s assets during $2021.$