Can someone please check my answers?

Question

Find the probability of drawing the given cards from a standard of 52 cards (a) with replacement and (b) without replacement.

1.A red card, then a black card
a. 1/4
b. 13/51

2.A ten, then the ace of hearts
a. 1/676
b. 1/663

3.A face card, then a two
a. 3/169
b. 4/221

4.A club, then a four
a. 1/52
b. 1/51

Answer 1

#1
a) 1/4 * 1/4
b) 1/4 * 13/51

#2
a) 1/13 * 1/52
b) 1/13 * 1/51

#3
a) 3/13 * 1/13
b) 3/13 * 4/51

#4
a) 1/4 * 1/13
b) 1/4 * (4/51 + 3/51)

Answer 2

A face card, then a 6