3,9,21,45,_

e Number Sequence: 3, 9, 21, 45, ?

To determine the next number in the sequence, we observe the pattern in the differences between consecutive terms:

• 9 - 3 = 6
• 21 - 9 = 12
• 45 - 21 = 24

These differences are: 6, 12, and 24, each doubling the previous difference. This suggests that the sequence follows a pattern where each term is obtained by adding twice the previous difference to the current term.

To find the next term:

• Next difference: 24 × 2 = 48
• Next term: 45 + 48 = 93

Therefore, the next number in the sequence is 93.