x barrels of this concrete, the number of barrells of cement used isA) x/5B) x/4C) xD) 4xE) 1/5xPlease explain.
The answer is A x/5 To make the concrete you need to have cement and sand. Say you have 1 barrel of cement, then to make the proper concrete mix you would need 4 barrels of sand (the 1:4 ratio of cement to sand) this would make 5 barrels of your concrete. So now we know that for every 5 barrels of concrete you need 1 (or 5/5) of cement, and thusly for every x barrels of concrete you would need x/5 barrels of cement. Hope This Helps.
The answer is C) x If x = 1, the barrel of cement is also 1 If x = 2, te barrel of cement is also 2 and so on
elementary math-wise > x/5 you add one volume of cement to four volumes of sands. they together make five volumes /actually less, since the cement will fill the hollows between the sand particles/ so you have a certain volume, of which one fifth 1/5 is cement making x barrels of concrete, one fifth of the x is the volume of cement you need. in the real world, htough, you will make no concrete of cement and SAND alone, you need shivel, or any larger fraction to make solid concrete. and water, of course. the e/ is not obvious it could be read as 1/(5x) in which case it is not similar to x/5, but you can read it as (1/5)*x in which case it is similar to the a/ i incline to read the 1/5x as 1 divided by x multiplied by five, which is not similar to the x divided by five.
B 1 part cement to 4 parts sand. If you made 10 barrels of concrete you would have 10 parts cement and 40 parts sand.
You'll understand it much better if you put in the form of a table of ratio of volumes: Cement Sand Concrete 1 part 4 parts Cement+sand=5 prts Cement: 1/5 of concrete Sand: 4/5 of concrete (After dividing parts of cement and sand by total volume (parts of concrete) Therefore if x barrels of concrete made, Volume of cement used =x/5 barrels Answer is A Moreover as some of others said answer A and E ARE NOT THE SAME! X/5 MEANS x divided by 5 1/5x , I suppose was initially written as 1 --- 5x in your paper, this means 1 divided by (5x) Hope I've been helpful and you're not confused...
