Answer:
540
Step-by-step explanation:
Amount of antifreeze in the 90% solution + amount of antifreeze in the 20% solution = amount of antifreeze in the 80% solution
0.90 x + 0.20 (90) = 0.80 (x + 90)
0.90 x + 18 = 0.80 x + 72
0.10 x = 54
x = 540
You need 540 gallons of 90% antifreeze solution.
Class of students - number of students that are boys = numbers of students that are girls
30 - 13 = 17
To change the number of students that are girls into percentage...
17/1 * 1/100 = 17/100
17/100 in a % form = 17%
The percentage of girls in the class is 17%
Answer:
Hi
Step-by-step explanation:
Answer:
r = -5
Step-by-step explanation:
common ratio (r) is found be dividing one term by its preceding term:
r = 275 ÷ -55 = -5
or, r = -55 ÷ 11 = -5
Therefore, r = -5