Quiz Discussion

A 6 × 6 grid is cut from an 8 × 8 chessboard. In how many ways can we put two identical coins, one on the black square and one on a white square on the grid, such that they are not placed in the same row or in the same column?

• 1] 216 ways
• 2] 324 ways
• 3] 144 ways
• 4] 108 ways

If a train runs at 40 kmph, it reaches its destination late by 11 minutes but if it runs at 50 kmph, it is late by 5 min only. The correct time for the train to complete its journey is :

• 1] 13 min
• 2] 15 min
• 3] 19 min
• 4] 21 min

Two men start together to walk a certain distance, one at 4 km/hr and another at 3 km/hr. The former arrives half an hour before the latter. Find the distance :

• 1] 8 km
• 2] 7 km
• 3] 6 km
• 4] 9 km

A ship leaves on a long voyage. When it is 18 miles from shore, a sea plane, whose speed is ten times that of the ship, is sent to deliver mail. How far from the shore does the sea plane catch up with the ship?

• 1] 24 miles
• 2] 25 miles
• 3] 22 miles
• 4] 20 miles
• 5] None of these

Two boats A and B start towards each other from two places, 108 km apart. Speed of the boats A and B in still water are 12 km/h and 15 km/h respectively. If A proceeds down and B up the stream, they will meet after:

• 1] 4.5 hours
• 2] 4 hours
• 3] 5.4 hours
• 4] 6 hours

One third of a certain journey is covered at the rate of 25 km/hr, one forth at the rate of 30 km/hr and the rest at 50 km/hr. The average speed for the whole journey is :

• 1]

  35 km/hr

• 2]

  \(33\frac{1}{3}\) km/hr

• 3]

  30 km/hr

• 4]

  \(37\frac{1}{12}\) km/hr

A student goes to school at the rate of \(2\frac{1}{2}\) km/hr and reaches 6 min late. If he travels at the speed of 3 km/hr he is 10 min early. What is the distance to the school?

• 1]

  4 km

• 2]

  \(3\frac{1}{4}\) km

• 3]

  1 km

• 4]

  \(3\frac{1}{2}\) km

A is 10 miles west of B. C is 30 miles north of B. D is 20 miles east of C. What is the distance from A to D ?

• 1]

  10 miles

• 2]

  30 miles

• 3]

  \(10\sqrt {10}  \) miles

• 4]

  \(10\sqrt {13}  \) miles

• 5]

  \(30\sqrt {2}  \) miles

Two cyclists start on a circular track from a given point but in opposite directions with speeds of 7 m/sec and 8 m/sec respectively. If the circumference of the circle is 300 metres, after what time will they meet at the starting point ?

• 1] 20 sec
• 2] 100 sec
• 3] 200 sec
• 4] 300 sec

Two men P and Q start a journey from the same place at a speed of 3 km/hr and \(3\frac{1}{2}\) km/hr respectively. If they move in the same direction then what is the distance of them after 4 hours?

• 1]

  3 km

• 2]

  \(2\frac{1}{2} \)km

• 3]

  2 km

• 4]

  \(\frac{1}{2}\) km