10. What is the age of the youngest child?

The sum of the ages of 5 children born at the interval of 3 years each is 50 years. What is the age of the youngest child?

Answer: 
4 years.

Explanation:
Let the ages of the children be x, (x + 3), (x + 6), (x + 9) and (x + 12) years.
Then, x + (x + 3) + (x + 6) + (x + 9) + (x + 12) = 50
     =>5x = 20
     =>x = 4.
Therefore, Age of the youngest child = x = 4 years.

9. Find the number.

When 75% of a number is added to 75, it results in the number itself. Find the number?

Answer:
300
Explanation:

Let the number be ‘x’. 75% of x can be written as 3/4x.

Given, 3/4x+75=x

Solving gives x=300.

8. Find the next no.

 7-3=10124
6+3=9279
5-2=763
11+2=132613
15-3=? ?

Answer: 
183612

7. Find the length of the wire.

A copper sphere of diameter 9 cm is melted and drawn into a wire of 2 mm diameter. The length of the wire is???

Answer:  
1093.5 mm or 1.1m (approx)
Explanation:
Volume of Sphere = Volume of wire(cylinder)
4(pi*R^3)/3 = pi*r^2*h
R=4.5 & r=1mm
h=1093.5 mm or 1.1m(approx)

6. Predict the output

main()
{
static int var = 5;
printf("%d ",var--);
if(var)
main();
}

Answer:
5 4 3 2 1
Explanation:
When static storage class is given, it is initialized once. The change in the value of a static variable is retained even between the function calls. Main is also treated like any other ordinary function, which can be called recursively.

5. Find the missing no?

Find the next term in the following series:
3, 5, 5, 19, 7, 41, 9, ?

Answer: 
71
Explanation:

The actual series is in this form

3, 3*2-1, 5, 5*4-1, 7, 7*6-1, 9, so the next term must be 9*8-1=71

4. How many bananas did he eat on the first day?

A man ate 100 bananas in five days,each day eating 6 more than the previous day. How many bananas did he eat on the first day?

Answer: 
8

3. What's the man's age?

A man is three times as old as his son. Five years later he will be two and a half times as old as his son.What's the man's age?

Answer: 
Age of the man = 45
Explanation:
Let the age of son & father be x & 3x.
After 5 yrs
son=x+5
father=3x+5
Also given,
2.5(x+5)=3x+5,
solving gives x=15.
fathers age=3x=45

2. Find the length of the wall.

If 20 men build a wall of length 56m in 6 days , what length of a similar wall can be build by 35 men in 3 days?

Answer: 
49m

1. Find the number.

What will be the 18th term in the following series?
0, 6, 6, 20, 20, 42,...?

Answer: 
342

Explanation: 
The series is of the form
(1*1)- 1
(2*2)+2
(3*3)- 3
(4*4)+ 4
(5*5)- 5
So the 18th term will be 
(18*18)+18=342.