Division is the inverse of the multiplication.
Here is the answer. First change 20cm in mm = 200mm
ratio = 70mm/200
= 7 : 20
Hope this helps! Mark brainly please!
Step-by-step explanation:
Answer:
The scale factor is = 0.75 ÷ 1.25 =
i.e. 3:5//
The original volume of the ballon, with radius r, is given by
V₀ = (4/3)πr³ in²
If the radius increases to (r+5) because of air input, the new volume is
V₁ = (4/3)π (r+5)³ in²
The difference in volume is the amount of air used to inflate the balloon.
The volume of air is
V = V₁ - V₀
= (4/3)π [r³ + 3r²(5) + 3r(5²) + 5³ - r³]
= (4/3)π (15r² + 75r + 125) in³
Answer: (4/3)π (15r² + 75r + 125) in³
