7. Remove the joker cards from a deck of playing cards, and randomly draw 5 cards from the remaining 52 cards. The probability that at least two of the cards have the same number (or letter $J, Q, K, A$) is $\qquad$ (calculate this probability value, accurate to 0.01).
In a deck of 52 cards, there are $C_{52}^{5}$ ways to randomly draw 5 cards. Considering the case where the numbers or letters on the 5 cards are all different, since there are 13 different numbers or letters, each with 4 cards, there are $C_{13}^{5} \cdot 4^{5}$ ways to draw. Let $E=$ “at least two cards have the same number or letter”,
then $P(\bar{E})=\frac{C_{13}^{5} \cdot 4^{5}}{C_{52}^{5}}=\frac{13 \cdot 12 \cdot 11 \cdot 10 \cdot 9 \cdot 4^{5}}{52 \cdot 51 \cdot 50 \cdot 49 \cdot 48}=\frac{33 \cdot 64}{17 \cdot 5 \cdot 49}=0.507$.
Therefore, $P(E)=1-P(\bar{E})=0.493 \approx 0.49$.