SOLUTION: 1. Grace has 16 jellybeans in her pocket. She has 8 red ones, 4 green ones and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure sh

Algebra ->  Probability-and-statistics -> SOLUTION: 1. Grace has 16 jellybeans in her pocket. She has 8 red ones, 4 green ones and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure sh      Log On


   

Question 75276: 1. Grace has 16 jellybeans in her pocket. She has 8 red ones, 4 green ones and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure she has one of each color?
2. Sally can paint a house in 4 hours and John can paint the same house in 6 hours. How long will it take for both of them to paint the house together?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
1. Grace has 16 jellybeans in her pocket. She has 8 red ones, 4 green ones and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure she has one of each color?
She might pick 8 red ones, then 4 green ones; the next one she picks will
result in her having at least one of each color.
So 8+4+1 picks will guarantee she meets the criteria.
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2. Sally can paint a house in 4 hours and John can paint the same house in 6 hours. How long will it take for both of them to paint the house together?
Sally DATA:
time= 4 hr/job ; rate=(1/4) job/hr
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John DATA:
time = 6 hr/job ; rate=(1/6) job/hr
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Together DATA:
time = x hr/job ; rate = (1/x) job/hr
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EQUATION:
rate + rate = rate together
1/4 + 1/6 = 1/x
Multiply thru by 12x to get:
3x + 2x = 12
5x=12
x= 2.4 hrs (Time to do the job together)
x= 2 hrs and 24 minutes
Cheers,
Stan H.