Solution:

16/81

Explanation:
It is a question of geometric progression but we can solve it step by step as well in case you are not aware of the formula.

At first bounce
The height at which the ball would have reached = 2/3 of the original height from which it was dropped.

At second bounce
The height at which the ball would have reached = 2/3 * 2/3 of the original height from which it was dropped.

At third bounce
The height at which the ball would have reached = 2/3 * 2/3 * 2/3 of the original height from which it was dropped.

At fourth bounce
The height at which the ball would have reached = 2/3 * 2/3 * 2/3 * 2/3 of the original height from which it was dropped.

Now, 2/3 * 2/3 * 2/3 * 2/3 = 16/81

Therefore, 16/81 of the original height from which the ball was dropped is the required fraction height.

Solution:

101

Assuming '?' is no. of runs needed by Ajit in 51st inning.
(50 * 50 + ?)/51 = 51
=>2500 + ? = 51 * 51
=> ? = 2601 - 2500
=> ? = 101 (Answer)

Solution:

Of course, the questions has so many details and so many figures, but you have to consider just a few things. First calculate how much time will it take the friends to meet. Since they are meeting half way, they have to travel 18 miles. At the speed of 6 MPH, they will be able to do it in three hours.

Now see the fact that the parrot will keep on flying for three hours at 20 MPH. Thus the total distance that will be covered will be 60 miles.

Solution:

b+g = 8

Explanation:
for b in range(1,99):
for g in range(1,99):
sum1=2*b*g+42
sum2=(b+g)*(b+g+1)
if(sum1==sum2):
print(b,g,sum1)

(b,g)=(3,5) => b+g=8

Solution:

The easiest method to solve this question will be to form equations.

From the first picture
Weight of Cat + Weight of Rabbit = 10 Kg ---- First Equation

From the second picture
Weight of Dog + Weight of Rabbit = 20 Kg ---- Second Equation

From third picture
Weight of Cat + Weight of Dog = 24 Kg ---- Third Equation

Add the first, second and the third equations.

2 (Weight of Cat) + 2 (Weight of Dog) + 2 (Weight of Rabbit) = 10 Kg + 20 Kg + 24 Kg
2 (Weight of Cat + Weight of Dog + Weight of Rabbit) = 54 Kg
Weight of Cat + Weight of Dog + Weight of Rabbit = 27 Kg

Solution:

20 spokes

Explanation:
360/S = A
360/(S +10) = A – 6
Thus there are 20 spokes in the wheel.

Solution:

Let us first calculate the total number of matches that will be placed:
9C2 * 2
= 9! / (2!7!) * 2
= 8 * 9
= 72
Therefore, every team will play 16 matches.

Let us now glance over the cases that are possible.

Case 1:
Let us say that Team A, Team B and Team C wins 14 matches each (they lose 1 match each from the other two teams), then the Team D can win only (16 - 3 * 2) = 10 matches.

Case 2:
Suppose that, the top 4 teams win 13 matches each.
Team A will win 13 matches and will lose 3 matches from Team B, Team C and Team D.
Team B will win 13 matches and will lose 3 matches from Team A, Team C and Team D.
Team C will win 13 matches and will lose 3 matches from Team A, Team B and Team D.
Team D will win 13 matches and will lose 3 matches from Team A, Team B and Team C.

If this case actually happens, then the Team E will be able to win 8 matches at maximum as Team A, Team B, Team C and Team D will win all the matches played by E.

Case 3:
Suppose that, the top 5 teams win 12 matches each.
Team A will win 12 matches and will lose 3 matches from Team B, Team C, Team D and Team E.
Team B will win 12 matches and will lose 3 matches from Team A, Team C, Team D and Team E.
Team C will win 12 matches and will lose 3 matches from Team A, Team B, Team D and Team E.
Team D will win 12 matches and will lose 3 matches from Team A, Team B, Team C and Team E.
Team E will win 12 matches and will lose 3 matches from Team A, Team B, Team C and Team D.

If this case actually happens, Team E will win 12 matches but it still won't be able to get into the playoffs assuming that it has the lowest run rate among all.

This implies that from case 2, it is evident that a team must win 13 matches at the least to confirm its position in the playoffs.

Solution:

The number is 37.

The missing guess can be either 24 or 50 and the missing difference is 8.

Solution:

60%

Explanation:
In all such cases where you have to find out the probability of anything with an already given situation, you have to use the formula for conditional probability.

In this case, you have to find out the probability that the second test was passed by a student given that he passed the first test already.

Therefore, P(Second/First) = P (First and Second)/ P (First)
= 0.25/0.42
=0.60
=60 %

Solution:

2/5

Explanation:
This problem can be solved with different approaches. Let us not go into the complicated generic stuff to avoid confusion and try to solve it with simpler means.

Let us find the results separately. There can be 4 different results that give the sum of 5 and there can be 6 different results that give the sum of 7.

Thus, the probability that we get the sum of 4 before the sum of 7 will be:
4/(4+6) = 4/10 = 2/5.