I suck ass at conversions and I've tried working this stupid shit out for hours. I just can't get the formulas in order or figure out where to go from where.



"A homeowner is building a concrete walkway from his front porch steps to his drive way, which is a distance of 30 feet. The walkway will be made of individually poured slabs that are 3 feet long by 30 inches wide and 4 inches thick. An  80 pound bag of concrete mix will make a slab that is 2 feet long by 1 foot wide by 4 inches deep and costs $4.50 per bag. Determine:

   a) How much this project will cost the homeowner.

   b) How many pounds of mixed concrete will have been used if 3/4 of a gallon of water was added to each bag, and a gallon of water weighs about 8 pounds."
The second problem...
"A gram of fat contains about 9 calories. If a quarter pound hamburger is made from ground beef that is 85% lean (15% fat), how many calories from fat will a person consume by eating just the meat?"
Math is my crutch. I suck at it, and especially conversion shit. Sometimes I get started but I don't know where to go from the place I've stopped, and I don't know what goes .............. I'm just fucked. This shit seems so simple but my retard brain can't comprehend this shit.

First thing is to simplify the problem and get everything into consistent units.  I'd suggest converting everything into inches for example from the mixture of feet and inches measurements.  Then multiply and you get cubic inches for volume, etc.

Second problem is just checking to see how many grams in a quarter pound, then multiply.
Google has an easy conversion engine:
https://www.google.com/search?q=grams+to+pounds+conversion
0.250 lbs = 113.3981 grams.

113.3981 x 0.15 x 9 = 153.0874 calories

The careful/correct way to do it is to include all the units in the formulas to make sure that your units are all correct also.  If you haven't ever done that before you can try working those out, when folks have been doing them for a long time they kind of mentally work out the units and just do the numbers.  IE,  Grams * (calories/grams) = calories * (grams/grams) = calories.

ETA:
I'll start on the first problem also.

Slab 24in x 12in x 4in = 1152 in^3 = 1 bag = 80 pounds concrete = 4.50 dollars

Desired walkway = 30 inches wide * 30 feet (360 inches) long * 4 inches thick = 43200 in^3

(43200 in^3/walkway) /(1152 in^3/bag) = 37.5 bags per walkway
37.5 bags * 80 pounds concrete per bag = 3000 pounds of concrete
37.5 bags * 0.75 gallons water per bag * 8 pounds per gallon =  225 pounds of water
3000 + 225 = 3225 pounds of mixed concrete

Assuming you can't buy half a bag of concrete, you'd need 38 bags so 38 * $4.50 = $171.00

Be careful, the second problem is a trick question! This can only be calculated accurately if the hamburger is eaten raw.



If cooked on a grill, much of the fat will drip through and burn in the fire.



If cooked in a fry pan, much of the fat will pool up in the pan and probably poured off, or at least left behind in the pan as the burger is removed.

A practical consideration, depends on if the supplied measurement is before or after cooking.

Thank you! I haven't had a chance to look over it in-depth. I'm in class now.



I've looked at probably 4-5 different formulas but I just can't wrap my head around it. You know of any way to make this easier for my crayon-eating brain?



 

You need to start off the problem by looking at the information given based on the question.

Start with question A. You only need to do one conversion for this. Inches to feet.
The walk is 30 feet long by 30 inches wide. 30 inches is 2.5 feet. Total area of the walk is 75 ft^2.
The problem tells you that one bag makes an area of 1 foot by 2 feet. Total of 2 ft^2.
75/2=37.5 bags
Assuming you're talking real world application then you will need to round up to 38.