A door alarm works in 72 out of 100 cases.
surveillance camera works in 68 out of 100 cases.
The probability that method A is used = 72/100
The probability that method B is used = 68/100
Since both method are used we find the probability of A and B
Probability ( A and B) = *
=
Answer:
1) $283.50
2) 65.21 meters.
Step-by-step explanation:
Part 1)
We know that a spool of ribbon holds 6.75 meters.
A craft club buys 21 spools.
So, the total length of ribbon bought is:
Each meter costs $2. So, the total cost will be:
Part 2)
A spool holds 6.75 meters.
We bought 21 of them, so that total length we have is 141.75 meters.
The club used 76.54 meters.
So, the amount of ribbon that is left is represented by:
Subtract:
So, 65.21 meters of ribbon will be left.
Answer:
Step-by-step explanation:
Given:
---
1st problem:
Distribute:
Combine like terms:
---
2nd problem:
Distribute -3 to first factor:
Use foil to simplify:
Replace with -1:
Combine like terms:
---
3rd problem:
Distribute 2 to the second factor:
Use foil to simplify:
Replace with -1:
Combine like terms:
----
4th problem:
Distribute:
Combine like terms:
Simplify: