Answer: 14 Hours
Step by step:
Start by listing the information from the problem.
The spaceship's average speed is 8 kilometers per second. You can write this as a fraction in two ways:
8 km
1 sec
or
1 sec
8 km
.
The spaceship needs to travel 403,200 kilometers.
The problem asks how long it will take the spaceship to travel 403,200 kilometers. The spaceship is moving at a rate of
1 sec
8 km
. Multiply so that the kilometers cancel out. The result will be in seconds.
403,200km
1sec
8km
=
403200kmsec
8km
=50400 sec
Now you know it will take the spaceship 50,400 seconds to reach the moon, but the problem asks about hours. So, convert the seconds to hours. If you don't know how many seconds are in an hour, you can first convert the seconds to minutes.
There are 60 seconds in 1 minute, so multiply by
1 min
60 sec
. The result will be in minutes since the units of seconds cancel out.
50,400sec
1min
60sec
=
50400secmin
60sec
=840 min
Now convert 840 minutes to hours. There are 60 minutes in 1 hour, so multiply by
1 hr
60 min
.
840min
1hr
60min
=
840minhr
60min
=14 hr
It will take the spaceship 14 hours to get to the moon.
Answer:
168.56 in²
Step-by-step explanation:
The area will be found by subtracting the area of the circle from the area of the square.
The area of the square will be given by A = 28(28) = 784 in².
The area of the circle will be given by A = 3.14(14²) = 3.14(196) = 615.44 in².
The area of the shaded portion is given by
784-615.44 = 168.56 in²
Answer:
C
Step-by-step explanation:
Hope this is right. Let me know if not! Have a nice day :)
Answer:
xy = 3
Step-by-step explanation:
The expression to be evaluated is:
By some algebraic handling:
Where:
There is one possible solution:
x = 3, y = 1
And consequently,
xy = 3
Answer:
(n+9)!/(n!9!)
Step-by-step explanation:
A combination is a selection of items from a collection, such that (unlike permutations) the order of selection does not matter.
This is a case of combination with repetition because any n-digit sequence can have numbers repeated. For example in the sequence 00238899 there are 2 zeros.
The formula to find the number of combinations when repetition is allowed is:
(n+N-1)!/[n!(N-1)!]
where
N is the number of elements of the set we can choose from
n is the number of elements we choose
In this case, the set {0,1,2,3,4,5,6,7,8,9} has 10 elements, N=10
The number of n-digit sequences is given by
(n+10-1)!/[n!(10-1)!]=(n+9)!/(n!9!)
