There are 720 ways through which 3 numbers can be selected from 10 numbers to open a keypad lock.
Given that there are 10 numbers are 3 numbers are required to open a keypad lock.
Permutations are the number of ways in which objects can be selected without replacements to form subsets.
It is expressed as n
=n!/(n-r)!.
Factorial of a number is the product of consecutive numbers less than the number.
Total numbers available=10
Numbers to be selected=3
Number of ways can be found by using permutations.
Number of ways =10
=10!/(10-3)!
=10!/7!
=10*9*8*7!/7!
=10*9*8
=720 ways.
Hence there are 720 ways through which 3 numbers can be selected from 10 numbers.
Learn more about permutations at brainly.com/question/1216161
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Answer: It will take him 1.68 years to recover his initial investment.
First, find the amount of extra money that he will make.
34,000 - 13,000 = 21,000
He will be making an extra 21,000 per year.
Now, divide the cost of his training by the amount of his increase.
35200 / 21000 = 1.68
That gives you the amount of years it will take him to pay off his investment.
No solution
3x+5+4x=7x+9
7x+5=7x+9
-7x -7x
you’re left with no x.. so no solution
Answer:
Step-by-step explanation:
Let the number of floors = x
Number of apartments per floor = 4x
4x *x = 100
4x² = 100
x² = 100/4
x² = 25
x =√25
x = 5
Number of apartments on each floor = 4*5 = 20