The skin's dermis is made of layers of cells, connective tissue and several structures that aid in maintaining its function. These structures include blood vessels, hair follicles, lymph vessels and glands.
XnY one color blind boy. 1  Probability of having a color blind daughter is (1/2 x 1/2) or 1/4 or 25% (0.25) This is because both sex and colorblindness are involved in the solution.  The probability that their first son is color blind is 50% (0.50). In this question only males are part of the solution.
The probability of not picking up an ace in the first attempt is 48/52. The probability of not picking an ace in the second attempt is 47/51. This is the case because you had previously removed one of the non-aces in the first attempt reducing the non-aces from 48 to 47. Also, the total amount of cards also dropped after the first attempt reducing the total number of cards from 52 to 51.