RS Aggarwal Class 8 Math Twelfth Chapter Direct Inverse Proportions Exercise 12C Solution
Tick (√) the correct answer in each of the following:
(1) If 14 kg of pulses cost Rs 882, what is cost of 22 kg of pulses?
Solution: 14 kg pulse cost Rs 882
Ans: (d) Rs 1386
(2) If 8 oranges cost Rs 52, how many oranges can be bought for Rs 169?
Solution: Rs 52 is cost of 8 oranges
Ans: (c) 26
(3) A machine fills 420 bottles in 3 hours. How many bottles will it fill in 5 hours?
Solution: In 3 hours a machine can fill 420 bottles
Ans: (b) 700
(4) A car is travelling at a uniform speed of 75 km/hr. How much distance will it cover in 20 minutes?
In 60 min the car travel 75 km
Ans: (a) 25 km
(5) The weight of 12 sheets of a thick paper is 40 grams. How many sheets would weigh 1 kg?
Solution: Weight 40 grams is weight of 12 sheets
Ans: (c) 300
(6) A pole 14 m high casts a shadow of 10m. At the same time, what will be the height of a tree, the length of whose shadow is 7 metres?
Solution: Length 10 m shadow is 14 m high pole
Ans: (b) 9.8 m
(7) A photograph of a bacteria enlarged 50000 times attains of 5 cm. the actual length of bacteria is
Solution: Let the actual length be x cm. Then,
Ans: (c) 10-4 cm
(8) 6 pipes fill a tank 120 minutes, then 5 pipes will fill it in
Solution: 6 pipes to fill a tank take 120 min
Ans: (b) 144 minutes
(9) 3 persons can build a wall in 4 days, then 4 persons can build it in
Solution: To complete the work 3 persons take 4 days
Ans: (b) 3 days
(10) A car takes 2 hours to reach a destination by travelling at 60 km/hr. How long will it take while travelling at 80 km/hr?
Solution: The car travel in 1 hour 60 km.
Therefore, the car in 2 hours = 120 km
If the car travel in 1 hour 80 km.
Ans: (a) 1 hr 30 min