The answer would be <span><span>f<span>−1</span></span><span>(x)</span></span>=<span>√<span>36+x</span></span>,<span>−<span>√<span>36+<span>x. I didn't know it in word form :(</span></span></span></span>
3 and 4 because girls might like the school while boys don't and because men might hate the towel but women might love it.
3 units is the answer you're looking for