1. For any number x such that 0<x<1 the denominator is always greater than the numerator.. by squaring or cubing the denominator becomes even bigger and the overall number becomes much smaller than the original.. that's why m^3 is the answer.. plug in values and check..

2. Let X and Y be the two jars.. as per the question.. equal amount of water was poured..
so X/4 = Y/3.. pouring the content of Y in X, essentially means doubling the quantity of X.. so X/4 + X/4 = X/2

i.e 1/2

3. let x be the number of oranges..
70% of (14 +x) = 14
solve for x.. we get x = 6

so oranges to be removed = 23 - 6 = 17

4. (100/12 + 150/10)*30 = 700

adding to the above post, you can also do #3 by setting up ratios.

apples::oranges = 14:23


14 :: 23
14 :: 23-x ---> subtracting x number of oranges

7 :: 3 ----> new ratio (70% apples and 30% oranges)

14/(23-x) = 7/3

42 = 161-7x

x = 17