Answer: Option B.

Step-by-step explanation:
If a varies directly with b then when a increases b it also increases by a factor k.
Then we can write that

We know that when a = 28 then b = 7. So



Therefore the equation of proportionality is:

So when
then:

Answer:
The correct answer should be 11
Step-by-step explanation:
Let me know if this is wrong and I will correct it if it is.
Answer:
CE = 10.
Step-by-step explanation:
EC / 25 = 6/15
EC = 25*6/15
EC = 10
In order to determine the number of pens present in the container, we need to set up equations from the given in the problem statement. We do as follows:
let x the number of pencils
y the number of pens
From the statement, 9 more pencils then pens in a container,
x = y + 9
From the statement, there are 25 writing utensils in the container in all,
x + y = 25
We use substitution method to calculate for x and y,
y + 9 + y = 25
2y = 16
y = 8
x = 17
Therefore, there are 8 pens in the container and 17 pencils.
Answer:
$80
Step-by-step explanation:
From the question, we are given The simple interest formula as I = Prt,
where l = simple interest on an amount= $40
t= years=5years
at a rate r= 10%
The rate= 10/100= 0.1
Then since we are looking for P, we can make P subject of formula from this expression;
I = Prt
P=I/rt
P= 40/(0.1 ×5)
P= 40/0.5
P= 80
therefore, the amount of money p that is needed is $80