Maths : Basic Numeracy

Q 358 / 370

UPSC CSE Prelims 2012

Two glasses of equal volume are respectively half and three-fourths filled with milk. They are then filled to the brim by adding water. Their contents are then poured into another vessel. What will be the ratio of milk to water in this vessel?

EXPLANATION

Correct Option (4)

To determine the ratio of milk to water in the combined vessel, we first calculate the individual quantities of milk and water from each glass. Let 'V' represent the equal volume of each glass.

  • For the first glass:
    • Quantity of milk = 12V
    • Quantity of water (added to fill the brim) = V−12V=12V
  • For the second glass:
    • Quantity of milk = 34V
    • Quantity of water (added to fill the brim) = V−34V=14V

When the contents of both glasses are poured into another vessel:

  • Total quantity of milk = 12V+34V=24V+34V=54V
  • Total quantity of water = 12V+14V=24V+14V=34V

The ratio of milk to water in the new vessel is:

Total MilkTotal Water=54V34V=53

Thus, the ratio of milk to water is 5 : 3.

Incorrect Options:

Options (1) 1 : 3, (2) 2 : 3, and (3) 3 : 2 are incorrect. These ratios do not align with the precise calculation of the combined quantities of milk and water derived from the problem statement. Any deviation from the calculated total quantities of milk and water would lead to these incorrect ratios.