Math, asked by Mantajali25, 6 months ago


 The numbers 8, x, 9 and 36 are in proportion. Find x.
 Ifx:15=8:12;findthevalueofx.
 If 4, x, 32 and 40 are in proportion, find the value of x.
 If x: y = 4: 5 and y: z = 6: 7; find x : y : z.
 The length and breadth of a rectangle are in the ratio 5: 4. If its length is 80
cm, find the breadth.
 Check whether the two ratios form a proportion or not:
(i) 6: 8 and 12: 16; (ii) 24: 28 and 36: 48
 The first, third and fourth terms of a proportion are 12, 8 and 14
respectively. Find the second term.
 If 4, x, 9 are in continued proportion, find the value x.
 The ratio of the length of a school ground to its width is 5: 2. Find its length if
the width is 40 metres.
 Express each of the following ratios in its simplest form:
(i) 60: 72
(ii) 324: 144
 Find the ratio of the following in the simplest form:
(i) 75 paise to Rs 3
(ii) 35 minutes to 45 minutes
(iii) 8 kg to 400 gm
(iv) 48 minutes to 1 hour
 Margarette works in a factory and earns Rs 955 per month. She saves Rs 185 per month from her earnings. Find the ratio of:
(i) her savings to her income
(ii) her income to her expenditure (iii) her savings to her expenditur

Answers

Answered by khashrul
13

Answer:

8, x, 9 and 36 are in proportion

x = 32

x:15 = 8:12

x = 10

4, x, 32 and 40 are in proportion

x = 5

x:y = 4:5 and y:z = 6:7

x:y:z = 24:30:35

The length and breadth of a rectangle are in the ratio 5:4

breadth = 64 cm

(i) 6:8 and 12:16

Yes, they form a proportion.

(ii) 24:28 and 36:48

No, they do not form a proportion.

If the second term is x, then:

x = 21

4, x, 9 are in continued proportion

∴ x = 6

Of a school ground:

length : width = 5 : 2

length = 100 metres

Express each of the following ratios in its simplest form:

(i) 60:72 = 5:6

(ii) 324 : 144 = 9:4

Find the ratio of the following in the simplest form:

(i) 75 paise to Rs 3 = 1:4

(ii) 35 minutes to 45 minutes = 7:9

(iii) 8 kg to 400 gm = 20:1

(iv) 48 minutes to 1 hour = 4:5

Margarette earns Rs 955 per month

She saves Rs 185 per month

∴ Her expenditures per month = Rs 770

The ratio of:

(i) savings to income = 37:191

(ii) income to expenditures = 191:154

(iii) savings to expenditures = 37:154

Step-by-step explanation:

8, x, 9 and 36 are in proportion

∴ Products of means = Product of extremes

∴ 9x = 8 . 36

∴ x = 32

x:15 = 8:12

∴ Products of means = Product of extremes

∴ 12x = 15 . 8

∴ x = 10

4, x, 32 and 40 are in proportion

∴ Products of means = Product of extremes

∴ 32x = 4 . 40

∴ x = 5

x:y = 4:5  

∴ 4y = 5x

∴ 28y = 35x

and  y:z = 6:7

∴ 7y = 6z

∴ 28y = 24z

∴ 35x = 28y = 24z

∴ x/24 = y/30 = z/35

∴ x:y:z = 24:30:35

The length and breadth of a rectangle are in the ratio 5:4

length : breadth = 5 : 4

∴ Products of means = Product of extremes

∴ 5 x breadth = 4 x length = 4 x 80 cm

∴ breadth = 64 cm

Check whether the two ratios form a proportion or not:

(i) 6:8 and 12:16

Product of the means = 8 x 12 = 96

Product of the extremes = 6 x 16 = 96

Yes they form a proportion.

(ii) 24:28 and 36:48

Product of the means = 28 x 36 = 4 x 7 x 3 x 12

Product of the extremes = 24 x 48 = 4 x 3 x 2 x 12 x 4

No they do not form a proportion.

If the second term is x, then:

12:x::8:14

∴ 8x = 12 . 14

∴ x = 21

4, x, 9 are in continued proportion

∴ x^2 = 4 . 9

∴ x = 6

Of a school ground:

length : width = 5 : 2

∴ 2 x length = 5 x width = 5 x 40 metres

∴ length = 100 metres

Express each of the following ratios in its simplest form:

(i) 60:72 = 5:6  [cancelling common factor 12]

(ii) 324 : 144 = 12x27 : 12x12 = 9:4

Find the ratio of the following in the simplest form:

(i) 75 paise to Rs 3 = 75:300 = 3:12 = 1:4

(ii) 35 minutes to 45 minutes = 35:45 = 7:9

(iii) 8 kg to 400 gm = 8000:400 = 20:1

(iv) 48 minutes to 1 hour = 48:60 = 4:5

Margarette earns Rs 955 per month

She saves Rs 185 per month

∴ Her expenditures per month = Rs (955 - 185) = Rs 770

The ratio of:

(i) savings to income = 185:955 = 37:191

(ii) income to expenditures = 955:770 = 191:154

(iii) savings to expenditures = 185:770 = 37:154

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