Problem # $2$: In a mixing vat there are initially $200$ litres of volatile liquid. $4$ litres of fresh liquid are added per hour, but $20\%$

of the current content of the vat is lost each hour due to evaporation. How many litres of liquid are there after $4$

hours?

Problem #$2$:

Your answer cannot

contain any decimal

points! $93\mathrm{.}728$

Enter your answer symbolically,

as in these examples

Please correct the following errors:

Problem #$2$: Your answer cannot contain any decimal points!