I need help with this one.
- Thread starter JCasey527
- Start date
Thank you Denis
Please read the whole page to help me with problem number one at the bottom.
Joseph
Please read the whole page to help me with problem number one at the bottom.
Joseph
Hi JCasey:
Are you a student? Have you learned yet what "30% of a quantity" means?
We would like to know which parts of the example (on that page) you find confusing. Time may not be well-spent typing another lesson for you, if you don't understand the first one.
If you desire to follow the lesson on that page, then the guess-and-check method explained in the example will work for both problems 1 and 2.
We need to know why you're stuck, in order to determine where to continue helping you. Please give us a clue, and be sure to read the forum guidelines; here's a link to the summary page.
Cheers
PS: If you already understand how to decrease a known quantity by some given percent, then here's something to consider.
Reducing a number by 25% is the same as taking 75% of the number because if you take 25% away there's 75% left (100-25=75).
Reducing a number by 61% is the same as taking 39% of the number because if you take 61% away there's 39% left (100-61=39).
Therefore, to calculate $300 less 30%, you may take 70% of $300.
Hi JCasey:
Are you a student? Have you learned yet what "30% of a quantity" means?
We would like to know which parts of the example (on that page) you find confusing. Time may not be well-spent typing another lesson for you, if you don't understand the first one.
If you desire to follow the lesson on that page, then the guess-and-check method explained in the example will work for both problems 1 and 2.
We need to know why you're stuck, in order to determine where to continue helping you. Please give us a clue, and be sure to read the forum guidelines; here's a link to the summary page.
Cheers
PS: If you already understand how to decrease a known quantity by some given percent, then here's something to consider.
Reducing a number by 25% is the same as taking 75% of the number because if you take 25% away there's 75% left (100-25=75).
Reducing a number by 61% is the same as taking 39% of the number because if you take 61% away there's 39% left (100-61=39).
Therefore, to calculate $300 less 30%, you may take 70% of $300.
Thank you for your reply.
I am stuck trying to understand how to apply the example to question one. I'm not sure if it's because the increase/decrease or reversed. All I know is that I've tried two dozen guesses and I'm not left with an answer that I can plug into the problem and it be true.
Example:
The initial amount of baseball cards is >100.
I guessed 150.
150 - 20% = 120
120 + 20% = 144
144 - 10 = 134
Am I correct to assume that 134 is to be 10 less than my guess? If so, how do I apply the logic of the example here?
No, JCasey. You're trying to get the amount after week two (your 144 result) to be 10 less than the amount at the beginning of week one (your guess of 150).
(Omit the step in red.)
So, with guessing 150, the difference between 150 and 144 is only 6. That difference is not big enough; we need 10.
Maybe a 'tricky' part in this exercise is realizing that you need to guess a larger amount, in order to make the difference larger. (Some people guess 150, hope to get 140, but get 144, then mistakenly conclude that they need to guess a smaller amount because 144 turned out too big.)
:smile:
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