Roger purchases two doughnuts and three cookies at a doughnut shop and is charged $3.30. Sam purchases five doughnuts and two cookies at the same shop for $4.95. All the doughnuts have the same price and all the cookies have the same price. Find the cost of one doughnut and find the cost of one cookie.

PLEASE HELP ME WITH THIS PROBLEM!!!
If you can

3c + 1d =3.30
2c + 5d = 4.95
Now solve by substitution.
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