alleryWhich of the following is equivalent to the ratio $4 : 5$?
- $5 : 4$
- $8 : 10$
- $4 : 10$
- $5 : 8$
Show answer and solution
Correct answer: B. $8 : 10$
Multiplying both terms of a ratio by the same non-zero number preserves it: $4 : 5 = 8 : 10$.
GMAT Ratio and Proportion — practice questions
Explore 14 free Ratio and Proportion questions in GMAT Quantitative Reasoning. Open each question or exercise to read its content, reference answers and available explanation.
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Showing questions 1–14 of 14.
Which of the following is equivalent to the ratio $4 : 5$?Read the answer and worked solution →Find the fourth proportional to $4$, $9$ and $12$.Read the answer and worked solution →Find the mean proportional between $16$ and $25$.Read the answer and worked solution →If $\dfrac{a}{b} = \dfrac{3}{5}$, find the value of $\dfrac{a+b}{a-b}$.Read the answer and worked solution →Find the compounded ratio of $(2 : 3)$, $(5 : 7)$ and $(4 : 9)$.Read the answer and worked solution →₹$5400$ is divided among A, B and C in the ratio $3 : 5 : 7$. How much does B receive?Read the answer and worked solution →A recipe uses dal and rice in the ratio 2:5. If 35 cups of rice are used, how many cups of dal are needed?Read the answer and worked solution →₹8400 is divided among A, B, C in the ratio 3:4:5. What is B's share?Read the answer and worked solution →The sides of two cubes are in the ratio 2:3. What is the ratio of their VOLUMES?Read the answer and worked solution →If a:b = 3:2, what is (a+b)/(a−b)?Read the answer and worked solution →A vendor mixes ₹40/kg rice with ₹60/kg rice to sell at ₹52/kg. What is the ratio of cheap to costly rice?Read the answer and worked solution →Speed and time are __________ proportional for a fixed distance.Read the answer and worked solution →A 100-litre tank contains milk. 10 litres are drawn out and replaced with water. This is done 3 times. How much milk remains?Read the answer and worked solution →In a 200-metre race, A beats B by 20 metres. What is the ratio of A's speed to B's speed?Read the answer and worked solution →
Worked practice questions
Find the fourth proportional to $4$, $9$ and $12$.
- $18$
- $21$
- $24$
- $27$
Show answer and solution
Correct answer: D. $27$
If $4 : 9 = 12 : x$, then by the product-of-means equals product-of-extremes rule, $4x = 9 \times 12 = 108$, so $x = 27$.
Find the mean proportional between $16$ and $25$.
- $18$
- $20$
- $22$
- $24$
Show answer and solution
Correct answer: B. $20$
Mean proportional $= \sqrt{a \times b} = \sqrt{16 \times 25} = \sqrt{400} = 20$.
Option A (18) is the arithmetic mean $(16+25)/2 \approx 20.5$ rounded down — close, but not the geometric mean asked for.
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