Solution:

10

Re. 1 = 3
Rs. 2 = 1
Rs: 5 = 3

Total=7

He gave him 3 extra => total of 10(answer)

Solution:

nineteen

Explanation:
worstcase (7purple+11yellow+1blue)

Solution:

1000

Explanation:
Total number of methods selecting three question out of five in one section = 5*4/2*1 = 10
Since there are three sections and selection has to be made in each of them
Total methods = 10*10*10 = 1000

Solution:

122 (58+64)

Explanation:
It contains two series
5 13 29 61
and
10 26 58

First series in incremented by 8 16 32
and
second series in incremented by 16 32 and 64(our solution)

Solution:

20

Explanation:
correct + wrong = 30
3correct-2wrong = 40

=>3correct-60+2correct = 40
=>5correct = 100
=>correct = 20 & wrong = 10

Solution:

140

Explanation:

Let X be the number of chocolate so you can write down this equation
X/2 + X/4 +X/5 +7 = X

Solving the above equation, X=140

Solution:

14

prime number(+1) series
2 3 5 7 11

Solution:

25

Explanation:
0.20x + 0.25y =11.25
x+y = 50
=> x + (11.25-x/5) * 4 = 50-
=> x/5 = 5
=> x=25

Solution:

20 Rupees

Solution:

A and B