15% - 40. -25 = 1500 percent take out the zero because they have zero value and your left with 15 which is 15%
Let numbers of books be 'b' and numbers of CDs be 'c'
We can set up two equations:
Equation [1] ⇒

Equation [2] ⇒

We are solving for the number of books and the number of CDs bought
When we have two equations in terms of two different variables;

and

, that we need to solve, then this becomes a simultaneous equation problem.
First, rearrange Equation [1] to make either

or

the subject:


Then we substitute

into Equation [2]






Now we know the value of

which is

, substitute this value into

we have

Answer:
Numbers of books = 13
Numbers of CDs = 7
Step-by-step explanation:
You have 5 digits.Youdonot say if duplication is allowed. I will assume not
For the first digit you have 5 choices. One of the 5 digits is gone.
You now have 4 digits to choose from. You pick one. Now you have but 3 left.
The total answer if 5*4*3*2*1 = 120
For this case we can make the following rule of three:
1 cup ----------------> 128 grams
x ----------------------> 192 grams
From here, we clear the value of x.
We have then:
x = (192/128) * (1)
x = 1.5
x = 1 1/2
Answer:
She needs about 1 1/2 cups.