13 is 23 less than 15 times a number

From three chocolate bars we can make at most five chocolate rabbits and have some leftover. what is the greatest possible number of chocolate rabbits that can be made from sixteen chocolate bars (maybe with some leftover)?

Liz had 140 pens and inna had 100 pens. after inna gave liz some pens, liz had 3 times as many pens as inna. how many pens did inna give liz?

If a line is defined by the equation y = 5x + 2, what is the slope?