Geometric sequences go up due to a common ratio. Here the common ratio can be worked out by dividing a term by its previous term e.g term 2 divided by term 1.

Therefore the common ratio is 6.
Answer:
75
Step-by-step explanation:
15 divided by .20 = 75
Answer:
7
Step-by-step explanation:
10+7+1+6+7+9+8+10+2+5
-----------------------------------
10
65 ÷ 10
= 6.5, round up, = 7
Step-by-step explanation:
Let the original speed of the train be x km/h.
Time taken to cover a distance of 360 km = 360/x hours.
New speed of the train = (x+5) km/h.
Time taken to cover a distance of 360 km at new speed = 360/x+5 hours.
Since, the train takes 1 hour less time,
∴360/x - 360/ x+5 = 1
⇒360 (5) = x² + 5x
⇒1800 = x² + 5x
⇒x² + 5x - 1800 = 0
⇒x² + 45x - 40x - 1800 = 0
⇒x (x+45) - 40( x +45) = 0
⇒(x+45) (x-40) = 0
⇒x = (-45), 40
But since speed cannot be in negative.
∴x = 40 km/hr.
Hence, the original speed of the train is 40 km/h.
The surface area of a cylinder that the radius tripled and it height is brought down to half is 3890.46 inches²
<h3 /><h3>How to find the surface area of a cylinder?</h3>
Surface area of a cylinder = 2πr(r + h)
Therefore,
radius is tripled = 3(7) = 21 inches
height is shrunk half its size = 17 / 2 = 8.5 inches
Therefore,
surface area = 2 × 3.14 × 21 (21 + 8.5)
surface area = 131.88(29.5)
surface area = 3890.46 inches²
learn more on cylinder here: brainly.com/question/16551354
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