$$x:y:z = {1 \over 2}:{1 \over 3}:{1 \over 4}$$

What is the value of $${{x + z - y} \over y}$$ = ?

Both the numerator and the denominator of $${3 \over 4}$$ are increased by a positive $${15 \over 17}$$ integer, x, and those of _____ are decreased by the same integer. This operation results in the same value for both the fractions. What is the value of x?

Two straight lines pass through the origin (x₀, y₀) = (0, 0). One of them passes through the point (x₁, y₁) = (1, 3) and the other passes through the point (x₂, y₂) = (1, 2). What is the area enclosed between the straight lines in the interval [0, 1] on the x-axis?

If

p : q = 1 : 2

q : r = 4 : 3

r : s = 4 : 5

and u is 50% more than s, what is the ratio p : u?