31. Find the missing number in 16, 33, 65, 131, 261, _____

Answer: 523

Explanation:

Each number is twice the preceding one with 1 added or subtracted alternatively.

So, the next number is (2 x 261 + 1) = 523.

30. A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is ?

Ans : 71.11 km/hr

Explanation:

Total time taken =		160	+	160	hrs.	=	9	hrs.
		64		80			2

Average speed =		320 x	2	km/hr	= 71.11 km/hr.
			9

29. P is the mother of K; K is the sister of D; D is the father of J. How is P related to J?

Answer: 

Grand mother

Explanation:

P is the mother of K

K is the sister of D

D is the father of J.

Therefore, J is the nephew or niece of K and P is the grandmother of J.

28. Find the output

Program:

main()
{
    int a[5] = {5, 1, 15, 20, 25};
    int i, j, m;
    i = ++a[1];
    j = a[1]++;
    m = a[i++];
    printf("%d, %d, %d", i, j, m);
}

Ans : 3,2,15

Explanation :

Step 1: int a[5] = {5, 1, 15, 20, 25}; The variable arr is declared as an integer array with a size of 5 and it is initialized to

a[0] = 5, a[1] = 1, a[2] = 15, a[3] = 20, a[4] = 25 .

Step 2: int i, j, m; The variable i,j,m are declared as an integer type.

Step 3: i = ++a[1]; becomes i = ++1; Hence i = 2 and a[1] = 2

Step 4: j = a[1]++; becomes j = 2++; Hence j = 2 and a[1] = 3.

Step 5: m = a[i++]; becomes m = a[2]; Hence m = 15 and i is incremented by 1(i++ means 2++ so i=3)

Step 6: printf("%d, %d, %d", i, j, m); It prints the value of the variables i, j, m

Hence the output of the program is 3, 2, 15

27. In how many ways can the letters of the word 'LEADER' be arranged?

Ans : 360


Explanation :

The word 'LEADER' contains 6 letters, namely 1L, 2E, 1A, 1D and 1R.

Required number of ways =	6!	= 360.
	(1!)(2!)(1!)(1!)(1!)

26. If a - b = 3 and a^2 + b^2 = 29, find the value of ab.

Ans :10

Explanation:
2ab = (a² + b²) - (a - b)²
   = 29 - 9 = 20
   ab = 10.

25. In how many ways can a group of 5 men and 2 women be made out of a total of 7 men and 3 women?

Answer: 63

Explanation:

Required number of ways = (7C5 x 3C2) = (7C2 x 3C1) =		7 x 6	x 3		= 63.
		2 x 1

24. Find the output.

void main()
{
int i=3, *j, k;
j = &i;
printf("%d\n", i**j*i+*j);
}

Answer: 
30

23. A triangle is made from a rope. The sides of the triangle are 25 cm, 11 cm and 31 cm. What will be the area of the square made from the same rope?

Solution: 

Add all sides 25+11+31 to get rope length rope length =67,rope is made in to as square. So side of square is 67/4=16.75 and so area is 16.75*16.75=280.5625.
Ans : 280.5625

22. If DDMUQZM is coded as CENTRAL then RBDJK can be coded as _____

Ans : QCEIL