Production function , profit maximization

[Jinx]

A firm has a production function Q=4√x and q is qty. Of output and input respectively. And price of output is 80 per unit and price of input is 20 per unit, then what will be the maximum profit that firm can earn?

[soimmoi]

didn't get your question
is this question from some entrance exam

[Amit Goyal]

Maximize 80(4√x) - 20 x with respect to x, and you will get

x = 64

Consequently, Q = 32.

[Jinx]

Yes. I found it in sample paper

[Jinx]

Thank you sir. I got it.