37. Find the output

main()
{
    float arr[] = {12.4, 2.3, 4.5, 6.7};
    printf("%d\n", sizeof(arr)/sizeof(arr[0]));
}

Answer: 4

Explanation:
The sizeof function return the given variable. Example: float a=10; sizeof(a) is 4 bytes
Step 1: float arr[] = {12.4, 2.3, 4.5, 6.7}; The variable arr is declared as an floating point array and it is initialized with the values.
Step 2: printf("%d\n", sizeof(arr)/sizeof(arr[0]));
The variable arr has 4 elements. The size of the float variable is 4 bytes.
Hence 4 elements x 4 bytes = 16 bytes
sizeof(arr[0]) is 4 bytes
Hence 16/4 is 4 bytes
Hence the output of the program is '4'.

36. How much does a watch lose per day, if its hands coincide ever 64 minutes?

Answer: 

32	8	min.
	11

Explanation:

55 min. spaces are covered in 60 min.

60 min. spaces are covered in		60	x 60	min.	= 65	5	min.
		55				11

Loss in 64 min. =		65	5	- 64		=	16	min.
			11				11

Loss in 24 hrs =		16	x	1	x 24 x 60	min.	=	32	8	min.
		11		64					11

35. Find the ouput.

#include<stdio.h>
int i;
int fun();

int main()
{
    while(i)
    {
        fun();
        main();
    }
    printf("Hello\n");
    return 0;
}
int fun()
{
    printf("Hi");
}

Answer: Hello
Explanation:
Step 1: int i; The variable i is declared as an integer type.
Step 1: int fun(); This prototype tells the compiler that the function fun() does not accept any arguments and it returns an integer value.
Step 1: while(i) The value of i is not initialized so this while condition is failed. So, it does not execute the while block.
Step 1: printf("Hello\n"); It prints "Hello".
Hence the output of the program is "Hello". 

34. An error 2% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is ?

Answer: 4.04%

Explanation:

100 cm is read as 102 cm.

 A₁ = (100 x 100) cm² and A₂ (102 x 102) cm².

(A₂ - A₁) = [(102)² - (100)²]

= (102 + 100) x (102 - 100)

= 404 cm².

Percentage error =		404	x 100	%	= 4.04%
		100 x 100

33. A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :

Answer: 8 days

Explanation:

(A + B + C)'s 1 day's work =	1	;
	6

(A + B)'s 1 day's work =	1	;
	8

(B + C)'s 1 day's work =	1	.
	12

(A + C)'s 1 day's work	= 2 x 1 - 1 + 1 6 8 12
	= 1 - 5 3 24
	= 3 24
	= 1 . 8

So, A and C together will do the work in 8 days.

32. Student A has secured 9 marks more than student B and A's marks was 56% of the sum of A&B's marks. The marks obtained by A and B are??

Answer: 

42,33

Explanation:

Let their marks be (x + 9) and x.

Then, x + 9 =	56	(x + 9 + x)
	100

 25(x + 9) = 14(2x + 9)

 3x = 99

 x = 33

So, their marks are 42 and 33.

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