Answer:
7/40
Step-by-step explanation:
There are 3 girls+9 boys = 12 students in the 7th grade
P (girl in 7th grade) = girls/ total
= 3/12 = 1/4
There are 7 girls+3 boys = 10 students in the 8th grade
P (girl in 8th grade) = girls/ total
= 7/10
P(7th grade girl, 8th grade girl) = 1/4 * 7/10 = 7/40
Answer:
I only know the second part sorry
9.35
Step-by-step explanation:
3(9)÷4+2.6=
27÷4+2.6=
6.75+2.6=
9.35
Answer:
This is an inverse variation, and the constant of variation is k = 2.
Step-by-step explanation:
Direct variation is something like:
y = k*x
Where k is the constant of variation.
So as x increases also increases y.
Inverse variation is something like:
y = k/x
k is the constant of variation.
In this case, if x increases, y decreases.
Now let's look at the equation:
-10 + 15*x*y = 20
Let's isolate y in one side of the equation:
15*x*y = 20 + 10 = 30
15*x*y = 30
y = 30/(15*x) = (30/15)/x = 2/x
y = 2/x
Then we can conclude that this is an inverse variation, with a constant of variation equal to 2.
1 day = 750 m
1 * 7 = 750 * 7
7 days = 5250 m
Now, since 1 km = 1000 m, this means in order to convert from meters to kilometers you must divide by 1000
5250 / 1000
= 5.25 km
Or, you could do the hard way by going to wolfram alpha / google and typing 5250 m to km.
Hope this helps!