# Search results

1. ### Need help with combination!

Q1. Phuong takes the 4 aces from a deck of cards and randomly selects an ace out of these 4 cards over 100 experiments. Find the probability that he selects the ace of hearts this number of times (to 3 significant figures). Q2. One bag contains 5 blue and 3 yellow balls and...
2. ### Need help with further proofs?

Find the coefficient of x^2 in (x+1/x)^3(x+1)^5 thanks
3. ### Need help with a factorial question (Binomial Theorem)

1. factorise k! + (k + 1) ! 2. Simplify (K-1)!/K! I don't understand the process of the solution! Can someone explain how to solve these 2 questions? Thank you!!!
4. ### Need help! please solve it with the series formula! (application of series)

Water evaporates from a pond at an average rate of 7% each week. (a) What percentage of water is left in the pond after (i) 1 week? (ii) 2 weeks? (iii) 3 weeks? (b) What percentage is left after 15 weeks? (c) If there was no rain, approximately how long would it take for the pond to...