M Dash Foundation: C Cube Learning

Tag: permutation-combination

  • A Question a day, Q4 (series)

    Question: Liliana has a bag of marbles. The bag contains 18 black, 15 red, 11 blue, and 8 white marbles. Liliana randomly takes a red marble from the bag and leaves the marble on a table. What is the probability that she will next take a red or a white marble from the bag?

  • Two beautiful theorems

    Thm-2; In the above expansion the sum of odd coefficient is same as the sum of even coefficient. put x=-1, then from above; 1+∑even- coefficients = ∑odd-coefficients = 1/2(∑all-coefficients) =