If there are 4 girls to every 9 students, then there are 5 boys to every girl, 9-4=5. So, there are more boys in the class.
Answer:
There are 36 peanuts in the bag.
Step-by-step explanation:
4 over 3;48 over x. 4x12=48 so 3x12=36
Answer:
10 milligrams
Step-by-step explanation:
Answer:
10 kph
Step-by-step explanation:
Find the speed of the current of the river.
20/(20 - c) + 180/(20 + c) = 8
20(20 + c) + 180(20 - c) = 8(400 - c^2)
8c^2 - 160c + 800 = 0
8(c^2 - 20c + 100) = 0
8(c - 10)^2 = 0
c = 10
The speed of the current of the river is 10 km/hour.