(9,40,41) is a Pythagorean Triple, farther down the list than teachers usually venture.
Answer: D. 41 cm
There's a subset of Pythagorean Triples where the long leg is one less than the hypotenuse,
a^2+b^2 = (b+1)^2
a^2 + b^2 = b^2 + 2b +1
a^2=2b+1
So we get one for every odd number, since the square of an odd number is odd and the square of an even number is even.
b = (a^2 - 1)/2
a=3, b=(3^2-1)/2=4, c=b+1=5
a=5, b=(5^2-1)/2 =12, c = 13
a=7, b=24, c=25
a=9, b=40, c=41
a=11, b=60, c=61
a=13, b=84, c=85
It's good to be able to recognize Pythagorean Triples when we see them.
Otherwise we'd have to work the calculator:
√(9² + 40²) = √1681 = 41
Given:
The system of inequalities is


To find:
The values of a for which the system has no solution.
Solution:
We have,
...(1)
It means the value of x is less than or equal to 5.
...(2)
It means the value of x is greater than or equal to a
Using (1) and (2), we get

But if a is great than 5, then there is no value of which satisfies this inequality.
Therefore, the system has no solution for a>5.
If Daniel has two minutes and each game lasts for 15 seconds then he has eight tries to win. ( 120 seconds divided by 15 seconds = 8) And if his odds are .1 that means he has a 10% chance each game. 10% x 8 tries = 80% chance. or .8