After the typist writes 40 letters and addresses 40 envelopes, she inserts the letters randomly into the envelopes (1 letter per envelope). What is the probability that exactly 1 letter is inserted in an improper envelope'?

The pace length P is the distance between the rear of two consecutive footprints. For men formula n/P = 144 gives approximate relationship between n and P where, n = number of steps per minute and P = pace length in meters. Bernard knows his pace length is 164cm. The formula applies to Bernard's walking. Calculate Bernard's walking speed in kmph.

43. There are two water tanks A and B, A is much smaller than B. While water fills at the rate of 1 liter every hour in A, it gets filled up like, 10, 20, 40, 80, 160 in tank B. (At the end of first hour, B has 10 liters, second hour it has 20 liters and so on). If tank B is 1/32 filled of the 21 hours, what is total duration of hours required to fill it completely?

21 people meet and shake hands. The maximum number of handshakes possible if there is no cycle of handshakes is

(A cycle of handshakes is a sequence of people a1, a2,....., ak such that the pairs (a1, a2), (a2, a3),.....(a(k-1), ak), (ak, a1) shake hands.

The teacher is testing a student's proficiency in arithmetic and poses the following question: 1/2 of a number is 5 more than 1/6 of the same number. What is the number? Can you help the student find the answer?

Ferrari S.P.A is an Italian sport car manufacturer based in Maranello, Italy. Founded by Enzo Ferrari in 1928 as Scuderia Ferrari,the company sponsored drivers and manufactured race cars before moving into production of street-legal vehicles in 1947 as Ferrari S.P.A. Throughout its history, the company has been noted for its continued participation in racing, especially in formula 1 where it has employed great success .Rohit once bought a Ferrari. It could go 4 times as fast as Mohan's old Mercedes. If the speed of Mohan's Mercedes is 35 km/hr and the distance traveled by the Ferrari is 490 km, find the total time taken by Rohit to drive that distance.

Alok and Bhanu play the following mm-max game. Given the expression N = 16+ X + Y - Z, where X, Y and Z are variables representing single digits (0 to 9), Alok would like to maximize N while Bhanu would like to minimize it. Towards this end, Alok chooses a single digit number and Bhanu substitutes this for a variable of her choice (X, Y or Z). Alok then chooses the next value and Bhanu, the variable to substitute the value. Finally Alok proposes the value for the remaining variable. Assuming both play to their optimal strategies, the value of N at the end of the game would be

A sheet of paper has statements numbered from 1 to 45. For all values of n from 1 to 45, statement n says at most n of the statements on this sheet are false . Which statements are true and which are false?

48 people {a1, a2, …… a48) meet and shake hands in a circular fashion. In other words, there are totally 48 handshakes involving the pairs, {a1, a2}, {a2, a3},……….. {a47, a48}, {a48, a1}. Then the size of the smallest set of people such that the rest have shaken hands with at least one person in the set is

9 years ago I was five times as old as my eldest son Today I am 3 times his age. HOW old am I now?

A lady has fine gloves and hats in her closet- 18 blue, 32 red, and 25 yellow. The lights are out and it is totally dark. In spite of the darkness, she can make out the difference between a hat and a glove. She takes out an item out of the closet only if she is sure that if it is a glove. How many gloves must she take out to make sure she has a pair of each color?

A group of friends Tom, Tina, Dick, Diana, Harry, and Harriet go out to a fair three hundred meters from the McDonalds which is five KMs away. They see a weighing machine and decide to have some fun. However the girls refuse to step on the weighing machine. So Tom, Dick and Harry, weigh themselves in a particular order. First Tom, Dick, and Harry weigh themselves individually and then Tom and Dick, Dick and Harry, Tom and Harry and then Tom, Dick and Harry together respectively. The recorded weight for the last measure is 161 kgs. The average of all the 7 measures is:

When a man weighing 5O Kg runs at an average speed of 10 Km/hrr, his rate of energy dissipation is four times higher than when he runs at an average speed of 3 Km hr. However, when a 60 Kg man runs at 12 Km hr: his rate of energy dissipation is only three times higher than when he runs at an average speed of 6 km hr. If a man walks at 4 mph over a certain journey and jogs back over the same route at 6 mph at an altitude of 200 meters. What is his average speed for the journey in mph?

The Thousand Pillar Temple of Hyderabad was built by the Kakatiyans of Chalukyan dynasty in the 12th century. Each pillar has carvings made of black monolithic rocks of basalt which are polished to give it a brilliant look. One sunny morning, three tourists visit the temple. Sandeep is taller than Richie and taller than two of the thousand pillars, and Jithesh is shorter than Sandeep and three pillars. Which of the following statements would be most accurate?

A green grocer was selling melon at a penny each, olives at 2 for a penny and grapes at 3 for a penny. A father spent 7p and got the same amount of each type of fruit for each of his three children, Jane, Joe, and Jill. Jane is three years older than Jill and Joe is exactly half the age of Jane and Jill together. What did each child get?

Susan made a block with small cubes of 6 cubic cm volume to make a block 6 small cubes long: 8 small cubes wide and 10 small cubes deep. She realises that she has used more small cubes than she really needed. She realized that she could have glued a fewer number of cubes together to look like a block. with same dimensions: if it were made hollow. What is the minimum number of cubes that she needs to make the block?

A race horse starts chasing a wild pony 2 hours after the pony bolts the stable. The pony runs through the entire county of Alberton: Texas jumping over three streams and crossing four 10 meter roads. The race horse finally catches up with the pony after 5 hours by which time the sun had set and the moon was up in the sky for 4 hours. If the average speed of the race horse is 84 kmph: then the average speed of the wild pony is …………………kmph.

Two blocks of Copper with density of 100Kg/m"3 are twisted into wires of length 100Km and thickness 0.1 mm. Copper is a very ductile material. Its ductility is measured in terms of percentage elongation upon application of tensile forces. The conductivity of the copper wire is extremely high rendering it useful in the construction of many electronic circuits. If the voltage through one such circuit is 14 V and the current flowing in the circuit is 215 mA. What is the resistance of the wire?

A toy train produces at least 10 different tunes when it moves around a circular toy track of radius 5 meters: at 10 meters per minute. However, the toy train is defective and it now produces only two different tunes at random. What are the odds that the toy train produces 3 consecutive music tunes of the some type (1 in ………….) ?

The difference between the ages of two of my three grandchildren is 3. My eldest grandchild is three times older than the age of my youngest grandchild and my eldest grandchild's age is two years more than the ages of my two youngest grandchildren added together. How old is my eldest grandchild?