To find how many pretzels were in the whole bag, we can take the information that Lisa ate 80 pretzels, which is 20% of the total bag.
Here's how you can approach the problem step by step:
-
Understanding the relationship:
- If 80 pretzels represent 20% of the total bag, we can set up the equation based on the percentage.
-
Setting up the equation:
- Since 20% corresponds to 80 pretzels, we can find 100% (the total) by using the fact that 100% is 5 times greater than 20% (because 100% divided by 20% equals 5).
- This leads us to the calculation:
- If 20% = 80 pretzels, then you can multiply 80 pretzels by 5 to find 100%:
- \(80 \text{ pretzels} \times 5 = 400 \text{ pretzels}\).
-
Checking the options provided:
-
Correct Steps:
- 100 × 4 = number of pretzels in the bag: This implies recognizing that 100% is 4 times 20%, which isn’t laid out clearly in the options, but we can use \(80 \text{ pretzels} \times 5\) for clarity.
- 100 × 4 = 400 pretzels: This correctly uses the multiplier to reach the final bag size.
-
Incorrect Steps:
- 20 × 4 = 80: This is not necessary to find the total number of pretzels in the bag.
- 20 + 60 = 80: This doesn't help find the total but just states a fact about parts of the 80 pretzels.
- 100 + 60 = number of pretzels in the bag: This isn't relevant to the percentage to total relationship.
- 100 + 60 = 160 pretzels: This is also incorrect as it misinterprets how to calculate the total.
-
Therefore, the correct options to find the number of pretzels in the whole bag are:
- 100 × 4 = number of pretzels in the bag.
- 100 × 4 = 400 pretzels.