Questions asked
A hexadecimal number consists of the digits {0, 1, 2 ,...,9,A,B,C,D,E,F}. How many 5 digit hexadecimal numbers have exactly two letters? Note: a hexadecimal number will not start with 0.
Four cards are selected from a standard deck of 52 cards. What is the probability that all four cards are a different suit?
How many length 4 alphabetical strings do not end with M or B?
How many strings of length 8 over the alphabet {X, Y, Z} have either exactly three X's or exactly four Y's?
How many different lengths 10 ternary strings (strings containing 0, 1, 2) contain at most two ones?
What is the closed form of the recurrence relation with the given characteristic equation and initial conditions? x² + 2x - 15 = 0, a0 = 1, a1 = 4