
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
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November 18th, 2016, 02:07 PM  #1 
Newbie Joined: Aug 2016 From: SantosSP / BRASIL Posts: 15 Thanks: 0  I need help!
(a) Using the concept of permutation with repetition, draw up and execute a plan of resolution that leads to determining the number of whole and not negative solutions of the equation: x 1 + x 2 + x 3 + ... + xn = p. (b) Solve the following problem: How differently can we buy 3 full juice boxes in a supermarket that sells flavors: pineapple, lemon, orange, grape, apple, mango and peach? Tip: Design an equation of this type in item (a), causing the problem appears if set in a particular case of this equation. Last edited by skipjack; December 8th, 2016 at 01:12 PM. 
December 8th, 2016, 09:53 AM  #2 
Newbie Joined: Dec 2016 From: Geneva Posts: 5 Thanks: 0 
For question a, you can imagine p elements being shared between n groups. Say you line up your p elements, and place the n1 limits between each groups. Counting the p elements and the limits, there are in all p+n1 'places'. You need to choose n1 to position your 'limits' or p of them to position your elements. There are p+n1Cn1 = p+n1Cp solutions to your problem. Question b is the same story. There are 3 juice boxes to be share through 7 fruit types. There are 9C6 = 9C3 = 84 possibilities. I hope I was helpful. Last edited by skipjack; December 8th, 2016 at 01:03 PM. 