CHARLES's Responses in WyzAnt Answers

Roman has the value for A correct but it would help if you also obtain the values for B and C and check your work. A key point of the problem as you mentioned in your reply to Allison is that the average value is 70 which means that (A + B + C)/3 = 70. The equations need to be rewritten to take this into account like so: (C/4 + C/2 + C)/3 = 70 which gives

 (C/4 + 2C/4 + 4C/4) = 210 after multiplying both sides by 3 and getting the fractions with the same denominator. Adding the 3 fractions gives 7C/4 = 210 and multiplying each side by 4 gives 7C = 840 which results in C = 120 ; B = C/2 = 60; A = B/2 = C/4 = 30. Check your work by getting the average like so (120+60+30)/3 = 70. Best wishes.

The question is more easily solved if you remember that at STP, 1 mole of gas occupies 22.4 L of volume. Thus 0.0100 mole would occupy 1/100 th of the 22.4 L or 0.224 L. To convert the answer to mL, just multiply the 0.224 L by the unit factor of 1000 mL / 1 L to get a value of 224 mL.

Terry has the side of the square correctly written out. If the problem is asking you about the sides of the rectangle as noted in the question I saw, then follow up Terry's calculation by figuring out each side of the rectangle using the original information:

First side of rectangle is X-3 so 12-3 gives you 9 and second side is X+4 which gives you 12+4 or 16. Either answer of 9 or 16 would be considered to be correct for the problem that asks "Find the length of one side of the rectangle". You can then check your work by calculating the area of the rectangle and comparing it to the area of the square: area of rectangle = 9X16=144 which is same as area of square 12X12=144 so we can be sure that the values 9 and 16 make sense.