straight$-$line depreciation to zero over the $4-$year life; zero salvage value; price $=$ Tk$.41$ ; variable costs $=$ Tk$.24$; fixed costs $=$ Tk$.189,000$; quantity sold $=90,000$ units; tax rate $=23$ percent. How sensitive is operating cash flow to changes in quantity sold?

$($c$)$ Fekdil Plc has a weighted average cost of capital of $9\mathrm{.}1$ percent. The company's cost of equity is $11$ percent and its cost of debt is $6\mathrm{.}4$ percent. The tax rate is $21$ percent. What is the company's debt$-$equity ratio?