Ans two questions based figure

1.Train A starts from station A at 11.am.Train B starts from station B at 12 noon.the speed of train A is 4 kmph,train B is 1 kmph for the first hour,2 kmph for the 2nd hour,3 kmph for the 3rd hour etc.At what time do the two trains meet? ans:2 PM

2.There is a coin collection.100 coins in all.4 peopke collect coins.Each collects a minimum of 10 coins.and each has different number of coins.the numbers are even. (4 questions based on this)

7.There are 80 coins.One coin is counterfeit in weight.How many minimum weighings are required to find out the counterfeit coin? Ans 4

8.There are 31 kgs of rice .With a 1 kg weight,Find out the minimum number of weighings required to weigh 31 kgs.

11.Two questions based on figure. Given at the end.

12.There are 2 cars moving in opposite directions.the distance between them is 300cm.They move forward for 100cm with a speed of 50 cm/s,and omes back 50 cms at 25cm/s.after how many seconds will the cars collide?

Make up a sequence so that the paintings may be arranged with the following rules.

1) The 5th slot is always empty.

Find the area of the square which is covered by the circle.

The area is 1/3 area of the square. Find the side of the square.