Understanding percentage questions, Help!

[Tekken_Player]

Hi all i am new to the forum and many thanks for taking time out of your day to read my question. Where this might be easy for you guys, I really need help on how to solve these type of % questions, here goes!
The wording is really throwing me off tackling the problem!

Bacteria increases by 31% every hour. If the starting mass of bacteria is 3 grams, what is the mass after a day?

Second one is this:

8% of the students in a college drop out of a course every week. If 4000 start, how many will be left after 10 weeks?

If you guys can help me with a formula or explain what and how you got the answer I would be eternally grateful!

 

[stapel]

I really need help on how to solve these type of % questions.... The wording is really throwing me off tackling the problem!

1. Bacteria increases by 31% every hour. If the starting mass of bacteria is 3 grams, what is the mass after a day?

2. 8% of the students in a college drop out of a course every week. If 4000 start, how many will be left after 10 weeks?

You posted this to the "Arithmetic" category and refer to these as "percentage" questions. However, they're actually exponential growth and decay exercises, requiring tools and formulas from algebra.

Have you taken any algebra at all, or any pre-algebra? We'll be glad to try to find some lesson links, so you can learn the material between "Arithmetic" and this stuff, but it will help to have some search parameters. Thank you!

 

[Tekken_Player]

You posted this to the "Arithmetic" category and refer to these as "percentage" questions. However, they're actually exponential growth and decay exercises, requiring tools and formulas from algebra.

Have you taken any algebra at all, or any pre-algebra? We'll be glad to try to find some lesson links, so you can learn the material between "Arithmetic" and this stuff, but it will help to have some search parameters. Thank you!

Hi there. I have no clue about algebra, I just found the question on a percentage worksheet!

 

[Tekken_Player]

Are you able to do this basic one:
$1000 is deposited in an account earning 6% annually.
No other deposits (or withdrawals) are made.
How much will be in the account 20 years later?

Hi there, no I don't know how to do it because I don't understand the question. Are you saying it's £1000 add 6% multiply 20? I just don't understand lol, can you tell me the solution of your question then I can find the answer to mine?

 

[stapel]

Hi there. I have no clue about algebra, I just found the question on a percentage worksheet!

So you're doing this NOT as part of a class? If so, then please tell us how far you have gotten in mathematics. Have you done anything with variables at all? Or do you need to start in early pre-algebra?

Thank you!

 

[Tekken_Player]

So you're doing this NOT as part of a class? If so, then please tell us how far you have gotten in mathematics. Have you done anything with variables at all? Or do you need to start in early pre-algebra?

Thank you!

Hi,

I am self teaching myself in maths. All I can remember about algebra was y = x or something like that, and I pretty much had an attitude of "as long as I can count my money I don't care about letters etc" - foolish attitude I had back then but now I want to learn it. Back at senior school which was years ago, we had an endless production line of supply teachers who were all useless. I've been going over various maths subjects and started working on percentages just recently. How on earth do I solve these problems?

 

[stapel]

I am self teaching myself in maths. All I can remember about algebra was y = x or something like that... How on earth do I solve these problems?

Um... You can do these by first learning pre-algebra, then beginning algebra, and then finally reaching this topic in intermediate algebra or maybe pre-calculus.

Obviously, that isn't something we can do for you in a simple forum posting. Since you haven't yet reached algebra, then you've got months of study ahead of you. Put this aside for now, and return to it in a few months, or maybe next year.

My best wishes to you in your studies!