You can solve this one by adding their rates, but you have to invert the numbers they give you to find the rate. Rate is measured in something per unit of time, and "per" indicates division. So the rates are: 1/3 of an hour (Sally) and 1/6 of an hour (Steve). So add the rates: 1/3 + 1/6 = 1/2. (1/3 is 2/6, and 2/6 + 1/6 = 3/6). Since their combined rate is 1/2 of a room in one hour, it takes them two hours to paint the room.
This answer makes sense: It takes Sally three hours by herself; with Steve's help, she's faster, but not THAT much faster, because he's pretty slow. You can often spot-check word problem answers like this by giving it a common sense once-over. If we came up with four hours, that would clearly be wrong: it should take her LONGER if she's getting help.
9514 1404 393
Answer:
(x, y) = (-2, -1) or (2, 1)
Step-by-step explanation:
Substitute for x in the first equation:
(2y)^2 +3(2y)y = 10
10y^2 = 10
y^2 = 1
y = ±1
x = 2y = ±2
Solutions are (x, y) = (-2, -1) or (2, 1).
5 packs of erasers and 3 packs of pencils each will have 60
Answer:
It is transversal because it can separate two lines and become n perpendicular
Step-by-step explanation:
