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.
Answer:
C
Step-by-step explanation:
Hi there!
In order to answer your question, you'll need to use the cross product method:
1 cup water → 1/4 cup sugar
10 cups water → X cup sugar
(<u>(1/4) × 10)</u> ÷ 1 = X cups sugar
<u>2.5 ÷ 1</u> = X cups sugar
2.5 = X cups sugar
Your answer is : Using 10 cups of water, you should add 2 and a half cups of sugar so that the large batch tastes the same as the test batch.
There you go! I really hope this helped, if there's anything just let me know! :)
Answer: 3/13
Step-by-step explanation:
3 red
10 silver
13 total
picking red: 3/13
