When clark was 7 years old he had 22 rare coins. each year clark added 15 coins to his collection. assuming clark does not sell or lose any coins, how old will clark be when he has 577 coins? a) 30 b) 31 c) 37 d) 44

It is c I think but not entirely sure

Hello! So, Clark had 22 rare coins when he was 7 years of age. 22 coins is the amount he already had and he collects 15 rare coins each year. Let's set up an equation like this:

22 + 15y = 577. 

We solve it like this, because that will give us the amount of years it will take to have a total of 577 coins. First, let's subtract 22 from both sides to get 15y = 555. Now, divide each side by 15 to isolate the "y". 555/15 is 37. It will take another 37 years for Clark to have 577 coins. But you're not done with this problem. You have to add 7 years, because that was his age when he had 22 coins. 37 + 7 = 44. Clark will be 44 years old when he has 577 coins. The answer is D: 44.

Note: In questions like this, be sure to not forget the initial amount, whether it'd be in years, money or in different ways. Be sure to look very carefully to make sure you are not missing anything. Otherwise, you may have your answer marked as incorrect. You can always set up equations like this in any situation to help get you to the correct answer.