Solution:

First shop: 80 pencils
80 * 5 paise = 400 paise = 4 rupees

Second Shop: 1 Pencil
1 * 1 = 1 Rupee

Third Shop: 19 pencils
19 * 5 rupees = 95 rupees

4 + 1 + 95 = 100 rupees.

Solution:

The odd number is 820670987.

If you add up the first three digits of all the numbers, it adds up to 14 except for the third option i.e. 820670987.

Solution:

It's a coin.

Solution:

102

Explanation:
The total number of animals in the zoo is one hundred and two i.e. thirty-four animals of each kind.

Since we already know that the number of each animal is same, each single deer, spider and cricket will have a total of eighteen legs.

Now, 612/18 = 34.

Therefore, total number of animals:
34 * 3 = 102

Solution:

Actually, there are two series in the question. If you separate the alternate places, you will find that the first series is:
0, 1, 2, 3, 4
Where the digits are multiple of 1.

The second series is:
0, 2, 4, 6, __
Here, the digits are progressing with the multiples of 2.
Therefore, the next digit will be 8.

Solution:

In the first observation, the time was 1:12. In the second observation, the time was 3:24.
Therefore, 2 hours and 12 minutes have elapsed.

Solution:

Let us denote the chocolates with p, q and r.
We can frame the following two equations now
p + q + r = 100 ------ (1)
5p + 3q + 0.5r = 100
or 10p + 6q + r = 200 ---- (2)

Now, 2*[(Eq. 2) - (Eq.1)]
9p + 5q = 100
from this equation'p' should be a multiple of 5
for p = 5 ; q = 11
for p = 10 ; q = 2
for p = 15 or more q becomes -ve

Therefore, the two possible answers are
p = 5, q = 11, r = 84
p = 10, q = 2, r = 88

Solution:

Alex was one third of his father's age when he was 14. This goes back 31 years when his father was 42 years old.

Solution:

20

Solution:

The person to get off at the first floor is Paul.
The person to get off at the second floor is Christy.
The person to get off at the third floor is Mistie.
The person to get off at the fourth floor is Mia.
The person to get off at the fifth floor is David.
The person to get off at the sixth floor is Lee.