Recommend opinion of the national scientists
Answer:
10.22
Step-by-step explanation:
2.45 * 10 =20.45 - 3.67 * 10 =30.67
30.67 - 20.45
30 - 20 = 10
.67 - .45 = .22
30.67 - 20.45 = 10.22
Answer:
B 10 times smaller so you were right
The range would be the difference between the lowest age and the highest age.
The highest age is 76, the lowest age is 30
The range is 76 - 30 = 46
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.
