Question

1. In a basket, there are white and red balls. What is the smallest number of balls you need to take out of the basket so that there are definitely two balls of the same color among them?
2. A drawer contains 10 pairs of socks. Each pair is either black or white. What is the minimum number of socks that must be drawn, at random, from the drawer to ensure that you have 3 pairs of all the same color socks? 3. A bowl contains 5 red balls and 5 white balls. Dorothy selects balls at random without looking at them. How many balls must she select to be sure she has at least two red balls?

Answer 1

Answer:

1. 3
2. 7
3. 7

Step-by-step explanation:

1. In 2 draws, you can get one of each, so a minimum of 3 draws will guarantee at least 2 of one color.

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2. A minimum of 3 socks must be drawn to ensure one pair. A minimum of 2 must be drawn to ensure an additional pair. For three pairs, 7 socks must be drawn.

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3. The first 5 balls drawn could be white, so an additional 2 must be drawn to ensure 2 red balls. To be sure of 2 red balls, 7 balls must be drawn.