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:
18 pounds = 48 pizzas
18 pounds = 48 pizzas 22.5 pounds = 60 pizzas
18 pounds = 48 pizzas 22.5 pounds = 60 pizzas 27 pounds = 72 pizzas
Step-by-step explanation:
1) because they are ratios you multiply 18 and 8 (18 × 8 = 144) then you divide 144 by 3 (144÷3 =48)
2) now you do the same thing multiply 22.5 and 48 (22.5 × 48= 1,080) and divide 1,080 by 18 (1,080 ÷ 18= 60)
3) multiply 27 times 60 (27 × 60= 1,620) now divide 1,620 by 22.5 (1,620 ÷ 22.5= 72)
The function y = 2.5x + 500 represents the total number of miles if the motor car race is 500 miles long, option (d) is correct.
<h3>What is a function?</h3>
It is defined as a special type of relationship, and they have a predefined domain and range according to the function every value in the domain is related to exactly one value in the range.
We have:
y represents the number of miles a motor car has left to go in the race
x represents the number of laps completed by the motor car
The total number of miles if we consider only circular speedways = 2.5x
The total number of miles:
y = 2.5x + 500 (because 500 is the constant)
Thus, the function y = 2.5x + 500 represents the total number of miles if the motor car race is 500 miles long option (d) is correct.
Learn more about the function here:
brainly.com/question/5245372
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