Direct and inverse proportion

If x and y are directly proportional and when x = 13, y = 39, which of the following is not a possible pair of corresponding values of x and y ?

• 1 and 3

• 17 and 51

• 30 and 10

• 6 and 18

Which of the following is in direct proportion?

• One side of a cuboid and its volume.

• Speed of a vehicle and the distance travelled in a fixed time interval.

• Change in weight and height among individuals.

• Number of pipes to fill a tank and the time required to fill the same tank.

Amrita takes 18 hours to travel 720 kilometres. Time taken by her to travel 360 kilometres is _______ hours.

If x and y are inversely proportional then _____ = k where k is positive constant.

10 metres of cloth cost Rs 1000. What will 4 metres cost ?

• Rs 400

• Rs 800

• Rs 200

• Rs 100

If 18 women can reap a field in 7 days, in what time can 6 women reap the same field ?

• 15 days

• 21 days

• 30 days

• 36 days.

A machine in a soft drink factory fills 600 bottles in 5 hours. How many bottles will it fill in 2 hours ?

• 120

• 180

• 150

• 240

40 cows can graze a field in 16 days. How many cows will graze the same field in 10 days ?

• 60

• 64

• 80

• 75

If x = ky and when y = 4, x = 8 then k =

• 1

• 2

• 3

• 4

x and y vary inversely with each other. If x = 15 when y = 6, then the value of x when y = 15 is

• 2

• 4

• 5

• 6