Compare the numbers in the following sequence and try to determine what the next number should be. 6, 9, 18, 21, 42, 45, ? now when i did the math i thought it might be 54 but i'm not sure can someone me or tell me if i'm right!

If you examine the numbers in the question above very well, you will discover that thy have a distinctive pattern. The pattern is this, you add 3 to the first number and then you multiply the next by 2. Lets go over the numbers now:
6 + 3 = 9
9 * 2 = 18
18 + 3 = 21
21 * 2 = 42
42 + 3 = 45
45 * 2 = 90
90 + 3 = 93
93 * 2 = 186, etc.
Thus, the next number after 45 is 90. 

Hold on lemme do the work