Proportional Reasoning - 2 | IT

Question 1

Viswanath made idlis by mixing 6 cups of rice with 3 cups of urad dal, while Puneet made idlis by mixing 4 cups of rice with 2 cups of urad dal. If cooked in the same way, would their idlis taste the same?

Check your answer with HomiSolve it yourself, then let Homi check your steps and spot mistakes.
Solution
Understand the Question
  • The taste of the idlis depends on the proportion (ratio) of rice to urad dal in the batter, not on the total quantity made.
  • If both Viswanath and Puneet use the same ratio of rice to urad dal, their idlis will taste the same.
  • We calculate and compare the ratio of rice:urad dal\text{rice} : \text{urad dal} for both preparations.

Step 1 · Calculate Viswanath's Ratio

For Viswanath:

RatioViswanath=Cups of riceCups of urad dal=63=2\begin{aligned} \text{Ratio}_{\text{Viswanath}} &= \dfrac{\text{Cups of rice}}{\text{Cups of urad dal}} \\[0.6em] &= \dfrac{6}{3} \\[0.6em] &= 2 \end{aligned}

This means Viswanath uses 22 parts rice for every 11 part urad dal (2:12 : 1).

Step 2 · Calculate Puneet's Ratio

For Puneet:

RatioPuneet=Cups of riceCups of urad dal=42=2\begin{aligned} \text{Ratio}_{\text{Puneet}} &= \dfrac{\text{Cups of rice}}{\text{Cups of urad dal}} \\[0.6em] &= \dfrac{4}{2} \\[0.6em] &= 2 \end{aligned}

This means Puneet also uses 22 parts rice for every 11 part urad dal (2:12 : 1).

Step 3 · Compare the Ratios

Comparing the two ratios: RatioViswanath=RatioPuneet=2\text{Ratio}_{\text{Viswanath}} = \text{Ratio}_{\text{Puneet}} = 2

Since the ratios of rice to urad dal are equal (2:12 : 1), their idlis will taste the same.

Answer

Yes, their idlis would taste the same.

Common Mistakes
  • Comparing Absolute Quantities: Thinking Viswanath's idlis will taste different because he used more cups (66 vs 44) of rice. Taste depends on the ratio, not the absolute amount.
  • Inconsistent Ratios: Comparing ricedal\dfrac{\text{rice}}{\text{dal}} for one person and dalrice\dfrac{\text{dal}}{\text{rice}} for the other.

More questions in IT

Q1

Viswanath made idlis by mixing 6 cups of rice with 3 cups of urad dal, while Puneet made idlis by mixing 4 cups of rice with 2 cups of urad dal. If cooked in the same way, would their idlis taste the same?

Q2

Have you noticed that in many maps there is a ratio given, usually in the lower right corner of the map? It usually contains 11 and a very large number, such as 1:60,00,0001 : 60,00,000. What does RF 1:60,00,000\text{RF } 1 : 60,00,000 mean? What does it indicate? Can you guess?

Q3

Convert 60,00,000 cm60,00,000 \text{ cm} to kilometres.

It is 60 km60 \text{ km}. Verify this.

Q4

Using the map above, can you find the geographical distance between Bengaluru and Chennai? Also, find the geographical distance between Mangaluru and Chennai.

[Hint: Use a ruler to find the distance between the cities on the map. Then, use the ratio given on the map to find the actual geographical distance.]

Q5

Try to find the distances between the same two pairs of cities with different maps that have different scales (ratios). Do they all give the same geographical distance, approximately?

Q6

Context: Puneeth's father went from Lucknow to Kanpur in 3 hours by riding his motorcycle at a speed of 30 km/h. If he takes a car instead and drives at 60 km/h, how long will it take him to reach Kanpur?

Q. Can we represent this problem with the following statement of proportionality — 30:60::3:x30 : 60 :: 3 : x? Will the travel time increase or decrease as the speed of the motorcycle increases?

← Back to Proportional Reasoning - 2