Your friend notes that gatorade has electrolytes like sodium and potassium chloride. he figures that if a few electrolytes are good for you, then a lot must be even better. following this logic, he adds nearly a tablespoonful of salt to his gatorade. what kind of solution is his gatorade now (hypotonic, isotonic, or hypertonic)? what will likely to happen to his cells if he drinks this liquid?

The solution should become hypertonic.

A solution will be called hypertonic if their oncotic/osmotic pressure is higher than the body fluid. When a hypertonic solution is administered, they will attract water from the nearby membrane. This will make a nearby cell become shrink as they lose water. This might be dangerous as the cells as they might go lysis if the amount of water loss is too many.
After the salt absorbed, it will be dumped by kidney into urine. But the salt will also attract water, so you will lose some fluid and might become dehydrated. This is why drinking sea water is dangerous because it will cause more fluid loss in urine.