Gisela has 135 CDs. Eleven are pop music. She has 3 times as many rock
CDs as she has classical. How many rock CDs does Gisela have?
125-11 = 124
124/4 = 31
So, 31 classical, 93 rock
Let's solve this step by step:
1. We know that Gisela has 135 CDs in total.
2. Out of the 135 CDs, 11 are pop music CDs.
3. Let's assume Gisela has x number of classical CDs.
4. We are also given that she has 3 times as many rock CDs as classical CDs.
So, we can set up the following equation to represent the given information:
rock CDs = 3 * classical CDs
5. Let's substitute x as the number of classical CDs in the equation:
rock CDs = 3 * x
6. We know that the total number of CDs is 135, which means:
total CDs = pop CDs + rock CDs + classical CDs
135 = 11 + rock CDs + x
7. We can now substitute the equation for rock CDs from step 5 into step 6:
135 = 11 + 3 * x + x
8. Simplify the equation:
135 = 11 + 4 * x
9. Subtract 11 from both sides of the equation:
135 - 11 = 4 * x
124 = 4 * x
10. Divide both sides of the equation by 4:
124 / 4 = x
31 = x
So, Gisela has 31 classical CDs.
11. Now, we can find the number of rock CDs using the equation from step 5:
rock CDs = 3 * classical CDs
rock CDs = 3 * 31
rock CDs = 93
Therefore, Gisela has 93 rock CDs.
To find out how many rock CDs Gisela has, we first need to determine the number of classical CDs she has.
We are given that Gisela has 135 CDs in total. And we know that 11 CDs are pop music. This means there are 135 - 11 = 124 CDs left which are either rock or classical.
Let's assume the number of classical CDs is x. According to the problem, Gisela has 3 times as many rock CDs as classical CDs. So the number of rock CDs would be 3 * x.
Now we can set up an equation to represent this information. The total number of CDs can be expressed as the sum of pop, rock, and classical CDs:
Pop CDs + Rock CDs + Classical CDs = Total CDs
11 + 3x + x = 135
Simplifying the equation:
4x + 11 = 135
4x = 135 - 11
4x = 124
To isolate x, we divide both sides of the equation by 4:
x = 124 / 4
x = 31
So, Gisela has 31 classical CDs. And since she has 3 times as many rock CDs as classical, she has 3 * 31 = 93 rock CDs.