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If x varies inversely as y and x = 4 whe...

If x varies inversely as y and x = 4 when y = 6, then when x = 3 the value of y is _______.

A

4

B

8

C

5

D

6

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The correct Answer is:
To solve the problem where \( x \) varies inversely as \( y \), we can follow these steps: ### Step 1: Understand the relationship Since \( x \) varies inversely as \( y \), we can express this relationship mathematically as: \[ x \cdot y = k \] where \( k \) is a constant. ### Step 2: Find the constant \( k \) We are given that \( x = 4 \) when \( y = 6 \). We can substitute these values into the equation to find \( k \): \[ k = x \cdot y = 4 \cdot 6 = 24 \] ### Step 3: Use the constant to find \( y \) when \( x = 3 \) Now we need to find the value of \( y \) when \( x = 3 \). We can use the constant \( k \) we found in the previous step: \[ x \cdot y = k \implies 3 \cdot y = 24 \] ### Step 4: Solve for \( y \) To find \( y \), we can rearrange the equation: \[ y = \frac{24}{3} = 8 \] ### Conclusion Thus, when \( x = 3 \), the value of \( y \) is: \[ \boxed{8} \]
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NCERT EXEMPLAR-DIRECT AND INVERSE PROPORTIONS -EXERCISES
  1. An auto rickshaw takes 3 hours to cover a distance of 36 km. If its sp...

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  2. If the thickness of a pile of 12 cardboard sheets is 45 mm, then the t...

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  3. If x varies inversely as y and x = 4 when y = 6, then when x = 3 the v...

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  4. In direct proportion a1/b1 = a2/b2

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  5. In case of inverse proportion a2b2

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  6. If the area occupied by 15 postal stamps is 60 cm^2, then the area occ...

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  7. If 45 persons can complete a work in 20 days, then the time taken by 7...

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  8. Devangi travels 50 m distance in 75 steps, then the distance travelled...

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  9. Two quantities x and y are said to vary directly with each other if fo...

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  10. When the speed is kept fixed, time and distance vary inversely with ea...

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  11. When the distance is kept fixed, speed and time vary directly with eac...

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  12. Length of a side of a square and its area vary directly with each othe...

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  13. Length of a side of an equilateral triangle and its perimeter vary inv...

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  14. If d varies directly as t^2 then we can write dt^2=k where k is some c...

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  15. If a tree 24 m high casts a shadow of 15 m, then the height of a pole ...

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  16. If x and y are in direct proportion, then (x – 1) and (y – 1) are also...

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  17. If x and y are in inverse proportion, then (x + 1) and (y + 1) are als...

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  18. If p and q are in inverse variation then (p + 2) and (q – 2) are also ...

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  19. If one angle of a triangle is kept fixed then the measure of the remai...

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  20. Direct variations if two quantities a and b vary with each other in su...

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