D is your answer because the bar is 4 and you must have an equal amount of plates on each side so it cannot be B. It goes up by 40 because of 2 plates on each side of the bar
You would get it wrong cause you haven’t answered anything
Answer:
See the attached figure which represents the problem.
As shown, AA₁ and BB₁ are the altitudes in acute △ABC.
△AA₁C is a right triangle at A₁
So, Cos x = adjacent/hypotenuse = A₁C/AC ⇒(1)
△BB₁C is a right triangle at B₁
So, Cos x = adjacent/hypotenuse = B₁C/BC ⇒(2)
From (1) and (2)
∴ A₁C/AC = B₁C/BC
using scissors method
∴ A₁C · BC = B₁C · AC
1. 10 boxes
2. about 20
3. 6x100 + (6x9)x10 + 6x8