Page 161 - Start Up Mathematics_8 (Non CCE)

Exemplar Problems

1. Assuming land to be uniformly fertile, the area of land and the yield on it vary:
(a) directly with each other.
(b) inversely with each other.
(c) neither directly nor inversely with each other.
(d) sometimes directly and sometimes inversely with each other.
2. If 12 pumps can empty a reservoir in 20 hours, then time required by 45 such pumps to empty the same
reservoir is _________ hours.
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3. If the area occupied by 15 postal stamps is 60 cm , then the area occupied by 120 such postal stamps will
be _________.
4. If p and q are in inverse variation then (p + 2) and (q – 2) are also in inverse proportion. (True/False)
5. The mass of an aluminium rod varies directly with its length. If a 16 cm long rod has a mass of 192 g,
find the length of the rod whose mass is 105 g.
6. At a particular time, the length of the shadow of Qutub Minar whose height is 72 m is 80 m. What will
be the height of an electric pole, the length of whose shadow at the same time is 1,000 cm?
7. A bowler throws a cricket ball at a speed of 120 km/h. How long does this ball take to travel a distance
of 20 m to reach the batsman?
8. There are 20 g of protein in 75 g of sauted fish. How many grams of protein is in 225 g of that fish?

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