Help Me with Math

Have you tried converting it to a decimal?


3:20=3+20/60=3+1/3=3.33 (okay, it repeats but forget about that for a minute.)
1:45=1+45/60=1+3/4=1.75
3.33-1.75=1.58

Now you just need to convert that back to minutes and hours. If I remember correctly...
1.58=1+0.58
0.58(60)=34.8 (but let's round that up to 35, 'kay?)
1.58 of an hour=1:35=1 hour and 35 minutes
3:20-1:45=1:35

I probably got the conversion back wrong, though.

 

No, it would just be 48 minutes, no hours. Where has your 1 hour come from?

 

And it's wrong.

 

So it's addition here?

Wow, this stuff is really confusing.

And it gets worse.

Ben wants to take 10 lb of chocolate on a trip. If he already has chocolate bars weighing 2 lb 8 oz and 4 lb, how much more chocolate does he need to take?

Additionally, a more simple question two questions back, I got wrong.

Carl purchased three packages of hamburger from the butcher. The first package weighed 3 lb 5 oz, the second package weighed 2 lb 9 oz, and the third package weighed 3 lb 6oz. What was the total weight of the three packages? Note: 16 oz = 1 lb.

My answer: 8 lb, 20oz

3 lb + 2 lb + 3 lb = 8 lb
5 oz + 9 oz + 6 oz = 20 oz

Their answer: 9 lb 4 oz

 

2 hours - 1 hour = 1 hour

 

Amaury, this is fairly trivial stuff. I agree that some people just don't get along with maths but even an 8 year old could answer this.

 

You converted those hours into minutes, so that doesn't count. If your answer is bigger than 60 minutes you have to convert it back, otherwise it's just 48 minutes.

 

And I did. Their answer, however, didn't agree with mine.

 

Clever remarks aside, I suggest you spend some more time on the basics of mathematics.

 

I know the basics.

I know how to do addition, subtraction, multiplication, and even division as long as the equation doesn't have really big numbers (e.g., I can do 108 / 12, which equals 9, but I can't do something like 56 / 4,345 without help from the instructor at the GED place).

 

56 / 4.345

When dividing by decimals an easy method is to try and change the decimals into a whole number.

For instance you could change 4.345 to 4345 by multiplying by 1000. This means you have to multiply 56 by 1000 aswell.

So your new question would look like this 56000/4345. This works out to be a very funny number but usually converting decimals to whole numbers is a good way to go.

 

See, Amaury, the thing is, irregular metric systems (lb-oz, hours-minutes-seconds, degrees) aren't taught correctly, as I can see here. What I mean is, there is a much simpler way to avoid this kind of mistake you're making, for pretty much any system.

You say, for instance, an hour is equal to 60 minutes. You got the hours->minutes conversion correctly, but to do minutes->hours, you only need to do a simple division: x minutes/60. If you get a remainder, which will happen in most cases, that's the extra minutes you're looking for. E.g., 700 minutes = 700/60 = 11 hours AND 40 minutes (the remainder from the division).

Same applies to oz->lb, only this time, the form is: x oz/16. Your answer is correct, although incomplete. You have 8 lb and 20 oz, but you can still divide 20 oz/16, which gives an adittional 1 lb and 4 oz (once again, the remainder). Total: 9 lb and 4 oz.

 

I explained that several posts ago. Well, kinda. I explained the conversion to decimals thing.

 

...calculator.

 

holy **** someone give this guy a calculator

 

3 lb, 8 oz.

Ben wants to take 10 pounds of chocolate, and he already has 6 pounds (2 + 4) and 8 ounces.
There are 16 ounces in a pound, so he has 6 and a half pounds.
Subtract 6 from 10 and you get four. Subtract the half a pound from the remaining four and you have 3 and a half.

So, Ben needs 3 pounds and 8 ounces in order to have 10 lb of chocolate.

 

You... kind of got the right answer, I suppose.

You see, there are sixteen ounces in a pound (which was even shown in the question itself). So, if you have twenty ounces, then it would be equivalent to one pound four ounces.

 

This is post-high school math? Good Lord, I've been doing this since elementary. Well, not the lbs/oz thing because I'm Canadian, but as long as I knew the conversions, I could have done this.

Is the American school system really this bad?

 

Depending on which state you live in, really, but even that's subjective. Most of my schooling was done where there wasn't too much funding and if you were good at sports, the teachers would automatically pass you (I'm not kidding here, the teachers did this) and yet I turned out okay. I knew this stuff in elementary school.