Each seat of first class, business class and economy class in an airplane occupies carpet area on the airplane's floor in ratio 4:2:1. The number of these seats in the airplane are in the ratio 1:2:8. Suppose that all the tickets in a class are offered at the same price, and these prices follow the former ratio. What is the contribution of the economy class to the airplane's revenue on a flight?

Three women, Isha, Nisha, and Sudha, earn a monthly salary in the ratio $3:4:5$. They also spend monthly in the ratio $3:5:6$, saving the rest. If Sudha's savings are $1/6$th of her income, what's the ratio of the three women's monthly savings?

A parcel's shipping cost is proportional to the square of its volume in cubic meters. Suppose we break the parcel into 3 packages in the ratio $2:3:5$ of its original volume, to qualify for lower shipping cost. If the savings are the equivalent of $\sqrt{6200}$ cubic meters, what was the original volume of the parcel?

Coins of INR $2, 5,$ and $10$ denominations are in a bag in the ratio of $30:20:10,$ of which the INR $5$ coins amount to INR $250.$ What is the total value of coins in the bag?

A painting contractor tells the owner of a large custom-built cupboard that the painting cost will be proportional to the square of a cupboard's surface area as measured in square-m. The owner dismantles the cupboard into 4 modules in the ratio 3:5:6:8 of its surface area, such that no new surfaces are required to be painted. If the owner's savings turn out to be Rs 1400 due to the dismantling, what was original painting cost quoted by the contractor?

Three women Swati, Khyati and Tripti earn a monthly salary in the ratio 3:4:5. They also invest part of this salary regularly each month, in the ratio 3:5:6, spending the rest. If Tripti spends a monthly amount that is $3/4^{th}$ of her income, what's the ratio of the three women's monthly spending, in the same order as mentioned above?