Question

10. Melinda's lights went out. She has 3 pairs of red socks in her drawer, 2 pairs of black socks, and 5 pairs of white socks. What is the minimum number of pairs she must remove from the drawer to ensure that she has a pair of each color?

A. 3
B. 5
C. 7
D. 9
E. 10

& how did you find the answer out?

Answer 1

under worst case scenario
first pair she draws will be white
2nd pair - white
3rd par - white
4th pair - white
5th pair - white
6th pair - red
7th pair - red
8th pair - red
9th pair - black

When she draws the 9th time we notice that she has drawn a pair of each socks.

Answer 2

how did you know how to do it?

Answer 3

so if a similar problem appears the answer will be less than 1 from the total?

Answer 4

worst case would give the highest number first...
find the worst case by sorting max --> min
for this question is 5, 3, 2

So, its 5*2+3*2+one pair of black =
10+6+2=18.
18/2 =9 pair

Answer 5

why mutiply by 2?

Answer 6

2 socks makes 1 pair of socks

Answer 7

kk thanks