Answer:
11.42 boxes
Step-by-step explanation:
For the first box bought, there is a 100% chance of getting a unique toy (since you still don't have any). E₁ = 1.
After that, there is a 4 in 5 chance of getting a unique toy from the next box, the expected number of boxes required is:

For the next unique toy, there is now a 3 in 5 chance of getting it:

Following that logic, there is a 2 in 5 chance of getting the 4th unique toy:

Finally, there is a 1 in 5 chance to get the last unique toy:

The expected number of boxes to obtain a full set is:

To find the speed you must write S= d/t so for the first one we will chang 15 m to b so it is = 0.25h so s=3/0.25h = 12km/h an why secand is 45 m to h = 0.75h so S=d/t S =12/0.75 =16 km/h the to find the totel speed we should + the speed together so 12 + 16 = 28 km/h
Answer:
Step-by-step explanation:
Let the base camp is point A and boats' locations after two hours are points B and C.
By connecting the three points together we get a triangle ABC with sides:
- AB = 50*2 = 100 km
- AC = 70*2 = 140 km
The angle between AB and AC is:
- 60 + 50 = 110 degrees (opposite directions from south)
We are looking for the distance BC, which can be found by using the law of cosines:
- BC² = AB² + AC² - 2AB*AC*cos ∠BAC
- BC² = 100² + 140² - 2*100*140*cos 110°
- BC² = 39176.56 (rounded)
- BC = √39176.56 = 197.93 km (rounded)
The distance between the boats is 197.93 km.
Answer:
f(1/3) = 9
Step-by-step explanation:
f(x)=1/x+2/x
Combine terms
f(x) = 3/x
f(1/3) = 3 / (1/3)
f(1/3) = 9
3 3/4 divided by 1/2 is 7 1/2.