Answer:
15
Step-by-step explanation:
let r represent red marbles then white = 2r + 5 and total is 20, thus
r + 2r + 5 = 20 ( subtract 5 from both sides )
3r = 15 ( divide both sides by 3 )
r = 5 ← number of red marbles
Thus number of white = 20 - 5 = 15
Due to a membership drive for a public television station, the current ;membership is 125% of what it was a year ago. The current membership is 1200. How many members did the station have last year
1/5 = 3/15
1/3 = 5/15
2/3 = 10/15
So no :)
Reason why:
You want to find the common denominator between all three fractions, so all fractions are the same proportions. So in this case, if you multiply 5*3 you get 15, making it the common denominator. Then since you multiplied the 5 in 1/5 by 3 to get 15, and you have to multiply the 3 in 1/3 and 2/3 by 5 to get 15, then you multiply the numerator by the same number.
Sorry I am terrible at explaining things. Hope this helped though!
The Lewis family and the Perry family each used their sprinklers last summer. The water output rate for the Lewis family's sprinkler was 15 L per hour. The water output rate for the Perry family's sprinkler was 40 L per hour. The families used their sprinklers for a combined total of 65 hours, resulting in a total water output of 1850 L . How long was each sprinkler used
Answer:
Hours of use of sprinkler by Lewis family is 30 hours.
Hours of use of sprinkler by Perry family is 35 hours.
Step-by-step explanation:
Let W = hours of use by Lewis family
65 - W = hours of use by Perry family
Then;
15W + 40*(65 - W) = 1850
15W + 2600 - 40W = 1850
(15 - 40)W = 1850 - 2600
-25W = −750
W = 750/25 = 30
Therefore;
W = 30
65 - W = 65 - 30 = 35
Hence,
Hours of use by Lewis family is 30 hours.
Hours of use by Perry family is 35 hours.
