In my opinion, the speaker heard the ghost.
Exactly 80 liters of 20% are needed.
Let quantity of 20% alcohol solution be added : x liters
Here is the work:
> x*20% + 40 * 50% = (x+40) * 30%
> x*0.2 + 40*0.5 = (x+40)*0.3 ..(converting percentages into decimal)
> 0.2x + 20 = 0.3x + 12
> 20-12 = 0.3x - 0.2x (Rearranging similar terms)
> 8 = 0.1 x
Hence x = 8/0.1
Ans 80 Litres
The approximate length of the diameter,d of the circle is 250 ft
<h3>How to find the diameter of a circle</h3>
Circumference of the circle = 250π
- Circumference of a circle = 2πr
250π = 2πr
250π / 2π = r
125 = r
Recall,
Radius, r of a circle = Diameter, d ÷ 2
125 = d/2
d = 125 × 2
d = 250
Therefore, the diameter of the circle is 250 ft
Learn more about circumference of a circle:
brainly.com/question/15673093
