You find the variable x or y in one of the lines of the problem and then substitute the value of the variable you first found into the other line of the problem to find the other variable. Then, you plug all of the values you found into either line/equation of the problem to ensure that one side of the equation you pick is equal to what is on the other side of the "=" symbol.
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^
5 years because when you divide 90 by 18 to get how many years it takes the tree to grow to 90 inches tall, you get 5.
I think the answer would be 0.6
