The sum is 160/(1-r)=1280 where r is the common ratio,
1/(1-r)=1280/160=8
Inverting we get 1-r=1/8, r=7/8.
Answer:
D
Step-by-step explanation:
If xy = 0 then x = 0 or y = 0
Assuming there are only three colors on the spinner (black, red and white,) the probability of landing on white can be found by subtracting the probabilities for black and red from 1. This gets you 0.16, or one-sixth.
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.