Tuesday, October 14, 2014

combinations in lottery

Virginia Lottery 1992
******Combination Games*******

Price is Right
"Pick a Pair"
6 items pick the two priced the same.

********MORE ON COMBINATIONS************
Suppose the State Lottery takes this form:
6 numbers are randomly chosen from 1 thru 49.
The customer picks 6 numbers.
If the person matches the 6 that were chosen by the State Committee,
they win the entire JACKPOT.
Sometimes this JACKPOT is over $20,000,000.

If the customer was able to buy EVERY POSSIBLE
COMBINATION of 6 numbers, they would have to win.

How many GROUPS of 6 are possible from
the 49 numbers?

In Math we call this 49 CHOOSE 6
or 49 COMBINATION 6
49 objects GROUPED 6 at a time







Some types of word problems are easily solved using Combinations:
Suppose that you are going to choose a small group of 3 items
from a larger group of 7 items.
You could list all the possible groups, if need be.
But, you can count the number of the possible groups
by just using COMBINATIONS.
7 choose 3 has _35__ possible groups

7! / (3! times 4!) = 35

(7*6*5*4*3*2*1*)
(3*2*1)(4*3*2*1)
Reduce by dividing top
and bottom by (4!)
= (7*6*5)/(3*2*1)
OR
LOOKING at PASCAL's TRIANGLESee the row with 1, 7, 21, 35, 35, 21, 7, 1?
7 choose NONE has _1_ possible group
7 choose 1 has _7_ possible groups
7 choose 2 has _21_ possible groups
7 choose 3 has _35_ possible groups
7 choose 4 has _35_ possible groups
7 choose 5 has _21_ possible groups
7 choose 6 has _7_ possible groups
7 choose 7 has _1_ possible groups


HOW ABOUT using the TI-83?

   






7 choose NONE has _1_ possible group
7 choose 1 has _7_ possible groups
7 choose 2 has _21_ possible groups
7 choose 3 has _35_ possible groups
7 choose 4 has _35_ possible groups
7 choose 5 has _21_ possible groups
7 choose 6 has _7_ possible groups
7 choose 7 has _1_ possible groups



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This forms Sierpiński triangle 
Learn more at:



Monday, May 19, 2014

Summer 2014 questions





















(click on picture for larger view!)

The solutions also appear at
along with some other puzzles.




I have not done a complete solution to #5



IF YOU CLICK ON A PROBLEM
YOU CAN SEE A LARGER VIEW!
(SCROLL DOWN FOR THE ANSWERS.)








HINT FOR #8
The ANSWER is MORE THAN 30.
#8 Is VERY SIMILAR to:

THE ANSWERS ARE HERE...
(CLICK ON THE PICTURE TO SEE BETTER!)



****************2nd half of the summer********************

The following problems are for Mid-June to July 20th:
(The solutions will appear after July 20th)

#9) How many positive integers are FACTORS of 540?
#10) How many FOUR-DIGIT integers
use each of the digits 1,2,3 and 4
EXACTLY ONCE and are DIVISIBLE by 11?

#11) The senior class at Cincy High School has 200 students.
156 of the students are attending a university in the fall.
67 students will be employed,
and 35 will be employed while 
attending a university.
How many students will NOT WORK or
attend a university?

#12) What is the sum of the 40 smallest multiples of 7?

#13) In the prime factorization of 100!
(one hundred FACTORIAL),
what is the power of 5?
**************************************
#9) How many positive integers are FACTORS of 540?
ANSWER to #9) 24 choices

#10) How many FOUR-DIGIT integers 
use each of the digits 1,2,3 and 4
EXACTLY ONCE and are DIVISIBLE by 11?
ANSWER to #10) 8 four-digit integers

#11) The senior class at Cincy High School has 200 students.
156 of the students are attending a university in the fall.
67 students will be employed, 
and 35 will be employed while 
attending a university. 
How many students will NOT WORK or
attend a university?
ANSWER to #11) 12 students will do neither

#12) What is the sum of the 40 smallest multiples of 7?
ANSWER to #12) 5740

#13) In the prime factorization of 100!
(one hundred FACTORIAL),
what is the power of 5?

ANSWER to #12) the power on 5 is 24

**************************************

#14) ELVIS is in the building!



A problem from the 6th grade contest -
Counting Rectangles
Another 5th/6th grade competition question: