Instructions

For the following questions answer them individually

Question 71

Out of the total production of iron from hematite, an ore of Iron, 20% of the ore gets wasted, and out of the remaming iron, only 25% is pure iron. If the pure iron obtained if a year from a mine of hematite Was 80,000 kg then the quantity of hematite mined from that mine in the year is?

Question 72

An express train without its rake can go 24 km an hour, and the speed is diminished by a quantity that varies as the square root of the number wagons attached .If it is known that it is four wagons its speed is 20 km/hthe greatest number of wagons with which the engine can just move is

Question 73

They are six boxes are numbered 1, 2, 3, 4, 5, 6. Each box is to be filled with either red or green balls in such a way that at least one box containing green balls are consecutively numbered .The total number of days in which these can be done is

Question 74

'N’ persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to cach other, sings a two-minute song one pair after the other. If the total time taken for singingis 28 minutes, what is ‘N’?

Question 75

Thirty six identical chairs must be arranged in rows with the same ntimber of chairs in each row. Each row must contain at least three chairs and there must beat least three rows. A row 1S parallel to the front of the room. How many different angementsare possible?

Question 76

In an examination, A obtains 10 percent less than the minimum number of marks required for passing. B obtains 11$$\frac{1}{9}$$ percent less than A. C obtains 41$$\frac{3}{17}$$ percent less than the number of marks obtained by A and B together. Does C pass the exam or fail?

Question 77

From a well shuffled pack of 52 cards, 3 cafds’are drawn successively, the first being replaced before the second is drawn and the second being replaced before the third is drawn. The probability that the first is black, the sec m isdiamond andthethirdis ace. is

Question 78

In a class, there are equal number of boys and girls. Two students are selected for a game.If the probabilty that the two students are girls is $$\frac{7}{29}$$,then what is the strength of the class?

Question 79

Two squares of sizé $$1\times1$$ are selected one after another from an $$8\times8$$ chessboard. The ‘probability that the two squares belong to different rows and different columns, is

Question 80

Virat was asked to multiply a two-digit number P by a three-digit number Q. But she mistakenly multiplied P by the number formed by writing the digits of Q in the reverse order, there by getting an answer which is 22770 more than the correct answer. What is the minimum possible sum of the digits of Q?