Answer:
7x+y=0
x+6y=5
x+y=0
Step-by-step explanation:
Yep!
Weighing #1: Start off by splitting the pile of 12 coins evenly into two piles, 6 in each pile. Put one pile on each side of the balance. The side that is weighed down has the fake coin it in. Ignore the other 6 coins.
Weighing #2: Now you have 6 coins left. Split the pile evenly again, 3 in each pile. Repeat the same process and put each pile on one side of the balance. The side that is weighed down has your fake coin in it. Ignore the other 3 coins.
Weighing #3: You have 3 coins left. Take two coins, whichever two you like, and weigh them. If they weigh the same, then the one you didn't weigh is the fake one. If one is heavier, then that heavier one is your fake coin.
Answer:
x = 5
Step-by-step explanation:
20(20-x)=300
1. Divide both sides by 20.
20(20-x)/20 = 300/20
2. Simplify.
20-x=15
3. Subtract 20 from both sides.
20-x-29=15-20
4. Simplify.
-x=-5
5. Divide both sides by -1.
-x/-1 = -5/-1
6. Simplify.
x=5
Answer:
0.606531 = 60.6531% probability that it will take between 2 and 132 minutes for the student to arrive at the library parking lot.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:
In which 
is the decay parameter.
The probability that x is lower or equal to a is given by:
Which has the following solution:
The probability of finding a value higher than x is:
Mean of 4 minutes
This means that 
Find the probability that it will take between 2 and 132 minutes for the student to arrive at the library parking lot:
This is:
In which
0.606531 = 60.6531% probability that it will take between 2 and 132 minutes for the student to arrive at the library parking lot.
Y=-5X which is the equation you use to figure out the answer
