Oof, this is surely a tough one. But, if I'm looking at this correctly, than I think you were in the right mindset when trying to figure both of them out. Like, for #18, think about the formula; P(B|A) = P(A and B)/P(A). So, based on the question, you can let not rolling a 1 on the blue cube be A, and rolling a 1 on the red cube be B. Now, personally, I prefer using the decimals when heading into the equations, but I'll convert the product into a fraction for the instruction's sake. 0.02777777778 + 0.13888888889 = 1/6. 1/6 ≈ 17.7%. You can do the same for #19, the overall outcome would be 5/6, which would be about 83%. Now, that's just me really attempting my hand at it, I will say, Math is far from my strong suite. But, in all honesty, I really am doing my best to help (and no, it's not because of what you offered, lol, more rather I want to help people who struggle with the same problems I do). Anyways, I hope this helps, and if you need more information, or anything, just let me know! Wish ya the best of luck!! ^u^
Here, I've attached a picture of the triangle that accompanies this explanation.
cot = = =
Now view the triangle.
PS. Angle theta will have a coordinate of (-, +) because it is in quadrant II.
sin of the angle would be opposite/hypotenuse, so sin =
cos of the angle would be adjacent/hypotenuse, so cos =
tan of the angle would be opposite/adjacent, so tan =
Division CANNOT be commutative, here is why
lets say the problem is 24÷4
it is obviously 6
but when you flip 24÷4, you get 4÷24
and... 4÷24 is 0.16666666
6 and 0.1666 is totally different :p
This is volume of a sphere.