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Ratio Class - 16(Variation - 3)
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Variation part - 3

## Bharat Gupta is teaching live on Unacademy Plus

Bharat Gupta
Engineer by degree Mathematician by Heart. Having 22 years of teaching experience. More than 20000 students selected.

U
MJ
at 7:30 sec. how did 900√2 came from 1800/√2. please explain. I didn't got it.
In bus journey question, how v=100
Ankit Kumar
a year ago
Do not get confused, be cautious, the question says, Diesal per kilometer, then in the first case it will be sqrt(100/50) and in the second case it will be sqrt(D/42)
Vanshika Gera
22 days ago
it's still not clear as how v is 100
sir why v= 100?
Anuraj jain
6 months ago
50km in 30 min so 100km in 1 hour
NK
Nitesh Kumar
6 months ago
50 km = 30 min v=d /t =50/30/60 50.2=100
NK
Nitesh Kumar
6 months ago
50 km = 30 min v=d /t =50/30/60 50.2=100
In the first question why u have subtracted(-) it in the last part? In the equation it is (+)
How did you get velocity as 100????? Why dont you reply sir?????????
Sanjay singh
a year ago
Given, distance 50 Km is travelled in 30 min. So velocity is distance travelled in an hour. So velocity is 100 km in 1 hour.
1. RATIO AND PROPORTION Class 17 (Variation part - 3)

2. Suppose y varies as the sum of two quantities of which one varies directly as x and the other as inversely as x. if y 6 when x4 and y 3 when x 3, then the value of y when x is 2: . 2 b. 3 c. 0 d. 2 3

3. Suppose y varies as the sum of two quantities of which one varies directly as x and the other as inversely as x. if y 6 when x4 and y 3 when x = 3, then the value of y when x is 2: a. 2 b. 3 c. 0 d. 2 3 a -P Con I 3 24 32 b

4. The price of a necklace varies directly as the no. of beads in it. Also, it varies directly as the square root of radius of a bead. The price of a necklace was Rs 150, when it had 75 beads each of radius 1 cm. Find the radius of each bead of necklace having 100 beads whose cost is Rs 600 a. 2 cm b. 3 cm c. 4 cm d. 9 cm

5. The price of a necklace varies directly as the no. of beads in it. Also, it varies directly as the square root of radius of a bead. The price of a necklace was Rs 150, when it had 75 beads each of radius 1 cm. Find the radius of each bead of necklace having 100 beads whose cost is Rs 600 a. 2 cm b. 3 cm c. 4 cm d. 9 cm

6. The duration of a Bus journey varies as the distance and inversely as the velocity, the velocity varies directly as the square root of the quantity of diesel per kilometre used, inversely as the number of passenger in the bus. In a journey of 50 km in 30 minutes with 18 passenger, 100 It of diesel is required. How many litre of diesel is required in a journey of 42 km in 28 minutes with 16 passengers a. 50.42 It b. 53.76 It c. 52.28 It d. 56 It

7. The duration of a Bus journey varies as the distance and inversely as the velocity, the velocity varies directly as the square root of the quantity of diesel per kilometre used, inversely as the number of passenger in the bus. In a journey of 50 km in 30 minutes with 18 passenger, 100 It of diesel is required. How many litre of diesel is required in a journey of 42 km in 28 minutes with 16 passengers. a. 50.42 It b. 53.76 It c. 52.28 It A k,d 6o IS 16 fa loo 2 2 di3 2

8. The price of a book varies as the no. of pages in it and inversely as the time periods in years that have elapsed since the date of purchasing. Two books costs the same, however, the no. of pages in the first book is triple of the second book. If the first book is sold 18 years ago, how long ago was the second book sold? a, 54 years b. 9 years c. 6 years d.3years

9. The price of a book varies as the no. of pages in it and inversely as the time periods in years that have elapsed since the date of purchasing. Two books costs the same, however, the no. of pages in the first boolk is triple of the second book. If the first book is sold 18 years ago, how long ago was the second book sold? a, 54 years b. 9 years c. 6 years d.3years ook -I Gooh - a o Tn 3 n 12