My Math Forum

My Math Forum (
-   Algebra (
-   -   Formula help (

LordRaaa May 15th, 2012 01:49 AM

Formula help
I've got this equation for blood alcohol content, and I need to find the BAC at certain times.

BAC equation:

B = (A/rW) * 100 - V t

where B = Bac, A is amount of alcohol in grams, r = 0.7, W is mass in grams, V is 0.015 and t is time since drinking.

I have to find bac with mass 75000 grams (75kgs), 50 grams of alcohol after 5 hours. I subbed it all in and the answer is 0.02, which is fine.

My question is, I need to find how long will it take for the BAC to be below 0.05 in the above question.

Is revision question, so please help me!

Thank you.

LordRaaa May 15th, 2012 01:50 AM

Re: Formula help
Would it just be setting b = 0.05 and solving for t?

I tried that and got 2.4

is that the right answer?

Denis May 15th, 2012 05:56 AM

Re: Formula help
Lordy, lordy...can you post your problem again, paying attention to Capitals and lowercase;
like, A and a would be 2 DIFFERENT variables :idea:

skipjack May 15th, 2012 10:01 AM

Presumably, BAC means "blood alcohol concentration".

All times are GMT -8. The time now is 08:47 AM.

Copyright © 2019 My Math Forum. All rights reserved.