If the income of both companies in 2020 was equal, what was the ratio of their expenditures (X:Y)?
Answer: B
Let the equal income be I. Let expenditures be E_X and E_Y.
For X in 2020, Profit=50%. So, I = E_X(1+0.50) = 1.5 E_X.
For Y in 2020, Profit=55%. So, I = E_Y(1+0.55) = 1.55 E_Y.
Therefore, 1.5 E_X = 1.55 E_Y.
The ratio E_X / E_Y = 1.55 / 1.5 = 155 / 150 = 31 / 30.
The ratio is 31:30.