## Ratio, Proportion

#### Ratio, Proportion

1. Total number of students in a class is 95. if the total number of girls in the class is 45, then the ratio of total number if boys to total number girls is
1. 9:10
2. 7:8
3. 10:9
4. 9:11

1. Let the total number of boys in the class be x.
Then, according to the question,
x + 45 = 95
x = 95 - 45 = 50

##### Correct Option: C

Let the total number of boys in the class be x.
Then, according to the question,
x + 45 = 95
x = 95 - 45 = 50

Hence, the required ratio of total number of boys to total number of girls = B:G = 50:45 = 10:9

1. The ratio of money with Ram and Gopal is 7 : 17 and that with Gopal and Krishan is 7: 17. If Ram has Rs. 490, Krishan has ?
1. Rs. 2890
2. Rs. 2330
3. Rs. 1190
4. Rs. 2680

1. Ram : Gopal = 7 : 17 = 49 : 119
Gopal : Krishan = 7 : 17 = 119 : 289
∴ Ram : Gopal : Krishan = 49 : 119 : 289

##### Correct Option: A

Ram : Gopal = 7 : 17 = 49 : 119
Gopal : Krishan = 7 : 17 = 119 : 289
∴ Ram : Gopal : Krishan = 49 : 119 : 289
⇒ Ram : Krishan = 49 : 289
Thus, 49 : 289 = 490 : N
&there N = 289 x 490 / 49
= Rs. 2890

1. The prices of a scooter and a television set are in the ratio 3 : 2. If a scooter costs Rs. 6000 more than the television set, the price of the television set is ?
1. Rs. 6000
2. Rs. 10000
3. Rs. 12000
4. Rs. 18000

1. Let the price of a scooter be Rs. 3x and that of a television set Rs. 2x.
Then, 3x - 2x = 6000

##### Correct Option: C

Let the price of a scooter be Rs. 3x and that of a television set Rs. 2x.
Then, 3x - 2x = 6000
⇒ x = 6000

∴ Cost of a television set = 2x
= Rs. 12000

1. If 8 : y = y : 18 , then y is equal to ?
1. 144
2. 72
3. 26
4. 12

1. ∵ 18 x 18 = y2
∴ y = √144 = 12

##### Correct Option: D

∵ 18 x 18 = y2
∴ y = √144 = 12

1. A circle and a square have same area. Therefore, the ratio of the side of the square and the radius of the circle is ?
1. π : 1
2. 1 : √π
3. 1 : π
4. π : 1

1. Let the side of the square be 'a' and let the radius of the circle be 'r'
Then, a2 = πr2
⇒ a2 / r2 = π
⇒ a / r = √π

##### Correct Option: A

Let the side of the square be 'a' and let the radius of the circle be 'r'
Then, a2 = πr2
⇒ a2 / r2 = π
⇒ a / r = √π
∴ a : r = √π : 1