Lark has forgotten her locker combination. It is a sequence of three numbers, each in the range from 1 to 30, inclusive. She knows that the first number is odd, the second number is even, and the third number is a multiple of 3. How many combinations could possibly be Lark's?
To find the number of possible combinations, I need to multiply the number of choices for each number in the sequence. For the first number, I have 15 choices, since there are 15 odd numbers from 1 to 30. For the second number, I have 15 choices as well, since there are 15 even numbers from 1 to 30. For the third number, I have 10 choices, since there are 10 multiples of 3 from 1 to 30. So the total number of possible combinations is 15 x 15 x 10 = 2250. 