May you please explain number 10 on translating between words and math?

Sure. (Admittedly, I went a little overboard with the wordiness of this one.)

Let’s just start with what we know. Gus’s expenses were $690. He wants to make a profit of at least 60% of that, or .

The question reminds you that , so now we can plug the expenses and profit numbers we know into the equation to see what his revenue needs to be:

If he’s going to sell 50 shirts at a whole dollar price and collect $1104 in revenue, what does his price need to be?

Because he needs to sell at whole dollar prices and collect more than $1104, his price should be $23 per shirt.