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There is a bag full of 30 different colored and/or patterned balls. How many different three ball combinations can you have if you pull three balls out of the bag?Part 2: Write down (in factorial form) the total number of possible combinations there are if you draw all the balls out of the bag one at a time.I am really stuck on part 2

User Heladio Amaya
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1 Answer

13 votes
13 votes
Answer:

a) 4060 different combinations

b) 30!

Step-by-step explanation:

Given:

Total balls of different patterns = 30

To find:

a) the different three-ball combinations one can have if 3 balls are pulled out of the bag

b) the total number of possible combinations there are if you draw all the balls out of the bag one at a time in factorial form

a) To determine the 3-ball combinations, we will apply combination as the order they are picked doesnot matter


\begin{gathered} for^^^\text{ the 3 ball comination = }^nC_r \\ where\text{ n = 30, r = 3} \\ \\ ^(30)C_3\text{ = }(30!)/((30-3)!3!) \\ ^(30)C_3\text{ = }(30!)/(27!3!)\text{= }(30*29*28*27!)/(27!*3*2*1) \\ \\ ^(30)C_3\text{ = 4060 different combinations} \end{gathered}

b) if you are to draw all the balls one at a time, then for the 1st it will be 30 possibilities, the next will reduce by 1 to 29 possibilities, followed by 28 possibilities, etc to the last number 1

The possible combination = 30 × 29 × 28 × 27 × 26 × 25 ......5 × 4 × 3 × 2 ×1

The above is an expansion of a number factorial. the number is 30

30! = 30 × 29 × 28 × 27 × 26 × 25 ......5 × 4 × 3 × 2 ×1

Hence, the total number of possible combinations when you draw all the balls out of the bag one at a time in factorial form is 30!

User Rap
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