NCERT Exemplar Solutions - Class 6 - Mathematics - Unit 8: Ratio & Proportion
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In questions 35 to 46, fill in the blanks to make the statements true.

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Question. 35

35. A ratio is a form of comparison by _____.

Answer

A ratio is a form of comparison by division.

Step by Step Solution

Ratios compare two quantities by dividing one by the other.

Question. 36

36. 20 m : 70 m = Rs 8 : Rs ____.

Answer

20 m : 70 m = Rs 8 : Rs 28.

Step by Step Solution

Simplify \(20:70=2:7\). Let \(8:x=2:7\Rightarrow x=\dfrac{8\times7}{2}=28\).

Question. 37

37. There is a number in the box \(\square\) such that \(\square,\;24,\;9,\;12\) are in proportion. The number in the box is ____.

Answer

There is a number in the box such that 18, 24, 9, 12 are in proportion. The number in the box is 18.

Step by Step Solution

Proportion means \(\dfrac{x}{24}=\dfrac{9}{12}=\dfrac{3}{4}\Rightarrow x=24\times\dfrac{3}{4}=18\).

Question. 38

38. If two ratios are equal, then they are in ____.

Answer

If two ratios are equal, then they are in proportion.

Step by Step Solution

Equality of two ratios defines a proportion: \(a:b=c:d\).

Question. 39

39. The ratio of the perimeter of the boundary of the shaded portion to the perimeter of the whole figure is ____.

Fig 8.2

Answer

The ratio is 3 : 7.

Step by Step Solution

From the grid (each square of unit length), the outer boundary has perimeter proportional to 28 units, and the shaded boundary has 12 units. Thus \(12:28=3:7\).

Question. 40

40. The ratio of the area of the shaded portion to that of the whole figure is ____.

Fig 8.2

Answer

The ratio is 1 : 6.

Step by Step Solution

Whole figure has 24 unit squares; shaded region has 4 unit squares. Hence area ratio \(4:24=1:6\).

Question. 41

41. Sleeping time of a python in a 24 hour clock is represented by the shaded portion in Fig. 8.3. The ratio of sleeping time to awaking time is ____.

Fig 8.3

Answer

The ratio is 3 : 1.

Step by Step Solution

Shaded portion shows 18 hours sleeping and 6 hours awake. \(18:6=3:1\).

Question. 42

42. A ratio expressed in lowest form has no common factor other than _____ in its terms.

Answer

A ratio expressed in lowest form has no common factor other than one in its terms.

Step by Step Solution

In lowest terms, numerator and denominator are co-prime (gcd = 1).

Question. 43

43. To find the ratio of two quantities, they must be expressed in ____ units.

Answer

To find the ratio of two quantities, they must be expressed in same units.

Step by Step Solution

Units must match before comparing by division.

Question. 44

44. Ratio of 5 paise to 25 paise is the same as the ratio of 20 paise to ____.

Answer

Ratio of 5 paise to 25 paise is the same as the ratio of 20 paise to 100 paise (i.e., 1 Rupee).

Step by Step Solution

\(5:25=1:5\). For \(20:x=1:5\Rightarrow x=100\) paise \(=1\) Rupee.

Question. 45

45. Saturn and Jupiter take 9 hours 56 minutes and 10 hours 40 minutes, respectively for one spin on their axes. The ratio of the time taken by Saturn and Jupiter in lowest form is ____.

Answer

The ratio is 149 : 160.

Step by Step Solution

Convert to minutes: Saturn \(=9\times60+56=596\) min; Jupiter \(=10\times60+40=640\) min. Ratio \(596:640\). Divide by 4: \(149:160\).

Question. 46

46. 10 g of caustic soda dissolved in 100 mL of water makes a solution of caustic soda. Amount of caustic soda needed for 1 litre of water to make the same type of solution is ____.

Answer

100 g.

Step by Step Solution

Maintain the same ratio (grams : mL): \(10:100= x:1000\Rightarrow x=10\times\dfrac{1000}{100}=100\) g.

Disclaimer:The questions are taken from NCERT Exemplar, which is the copyright of NCERT. The solutions provided here are prepared independently for educational purposes only. This material is not an official NCERT publication.