Instructions

For the following questions answer them individually

Question 41

Two coal loading machines, each working 12 hours per day for 8 days, handle 9000 tonnes of coal with an efficiency of 90%; while 3 other coal loading machines at an efficiency of 80% are set to handle 12000 tonnes of coal in 6 days. How many hours per day should each machine

work?

Question 42

Six pipes are fitted to a water tank. Some of these are inlet pipes and the others outlet pipes. Each inlet pipe can fill the tank in 9 hours and each outlet pipe can empty the tank in 6 hours. On openingall the pipes, an empty tank is filled in 9 hours. The number of inlet pipes is .......

Question 43

A student purchased a computer system and a colour printer. If he sold the computer system at 10% loss and the colour printer at 20%gain, he would not lose anything. But if he sells the computer system at 5% gain and the colour printer at 15% loss, he would lose â‚¹800 in the bargain. How much did hepayfor the colour printer?

Question 44

Suppose that a maximum of 25 gm of salt dissolves in 100 gm of water. Any more salt, if added, remains undissolved and a sediment falls at the bottom. Now, water is evaporated from 1 kg of a 4% solution at the rate of 28 gm per hour. After how long will it start sedimenting

approximately?

Question 45

In a defective 6-faced die with numbers 1 to 6 inscribed, the probability of getting an odd number is twice the probability of getting an even number. Find the probability of getting a 2-digit prime number on 2 successive throws of the die.

Question 46

The fuel indicator in a car shows $$\frac{1}{5}th$$ of the fuel tank as full. When 22 more litres of fuel is poured into the tank, the indicator rests at three-fourth of the full mark. What is the capacity of the fuel tank?

Question 47

A sum of money is accumulating at compoundinterest at a certain rate of interest. If simple interest instead of compound were reckoned, the interest for the first two years would be diminished by â‚¹20 and that for thefirst three years by â‚¹61. What is the sum?

Question 48

A jar full of milk contains 40% water, A part of this milk is replaced by another containing 19% water and now the percentage of water is found to be 26%. The quantity of milk replaced is ........

Question 49

A fair coin is tossed repeatedly, If head appears on the first four tosses, then the probability of appearance of tail on the fifth toss is ..........

Question 50

The electricity bill of a certain establishment is partly fixed and partly varies with the number of units of electricity consumed. When in a certain month 540 units are consumed, the bill is â‚¹1800. Im another month 620 units are consumed and the bill 16 â‚¹2040. In yet another month 500 units are consumed. Thebill for that month would be ..........