Answer:
80 parrots were purchased.
Step-by-step explanation:
Let the total number of parrots be k.
If 20% (or 20/100 = 1/5) flew away and 5% (5/100 = 1/20) died, the remaining parrots will be k – (¹/₅k + ¹/₂₀k) = k – ¼k = ¾k.
Of the remaining, 45% (or 45/100 = 9/20) were sold, which means the total number of sold parrots will be ¾k × ⁹/₂₀ = ²⁷/₈₀k.
The remaining parrots = ¾k – ²⁷/₈₀k = ³³/₈₀k = 33
k = 33 × ⁸⁰/₃₃ = 80 parrots were purchased.
Answer:
The average speed of car is 67 kilometers per hour.
Step-by-step explanation:
Given that:
Distance travelled in one hour = 45 km
Distance travelled in next 2 hours = 78*2 = 156 km
Total distance = 45+156 = 201
Total time = 1+2 = 3 hours
Average speed of the car = 
Average speed of the car = 
Average speed of the car = 67 km/hr
Hence,
The average speed of car is 67 kilometers per hour.
blue marbles
y = yellow marbles
Sum = b+y
The <span>chance of a blue marble being drawn first is:
b / (b+y) = 0.55
</span>The <span>chance of a blue marble being drawn first then a yellow next is:
</span>b / (b+y) * y / (b+y-1) = 0.37
This can be solve easily by using a theorem of Bayes
0.37/0.55 = .67 or 67%
