#131 - Biased Coin Puzzle

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

First let us assume that all other condition are fair here.
Now the toss will generate a 52:48 distribution in the favour of heads. Therefore, the toss bias factor for heads is 52/48.

In the same manner, the coin will be generating 49:51 distribution in favour of tails which makes the coin bias factor for heads in this case to be 49/51.

So, we have a combined bias factor of (52 * 49) / (51 * 48) = 2548 / 2448 which will be cancelled by a 2448 / 2548 floor factor.
The floor will be generating a distribution of 2448 / (2548 + 2448) : 2548 / (2548 + 2448) in the favour of tails which amounts to 51.00080064% tails approximately.

#132 - Easy Maths Problem

A chocolate costs 6 rupees and a soda costs 5 rupees. If you have 32 rupees in total, how many chocolates and how many sodas can be purchased with that amount.

As per the given data,
6 * number of chocolates + 5 * number of sodas = 32

Now, we know that chocolates and sodas are definitely whole numbers; their respective values will be 2 and 4.

#133 - Which Coins Puzzle

Aman is having 1.15 rupees in his pocket. There are a total of 6 coins in his pocket.

When his friend asked him for a change, he was unable to given change for a rupee and five paisa.


Can you tell which coins did he have?

Aman had a 50p, a 25p and four 10p coins.

#134 - How Many Cartons Puzzle

Riya can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can she place sixty-six boxes in total ?

The total number of cartons required = 9.

5 cartons for large boxes = 5 * 6 = 30
4 cartons for small boxes = 4 * 9 = 36

30 + 36 = 66.

#135 - What The Code Puzzle

A man desired to get into his work building, however he had forgotten his code.
However, he did recollect five pieces of information
* Fifth number + Third number = 14
* The fourth number is one more than the second number.
* The first number is one less than twice the second number.
* The second number and the third number equals 10.
* The sum of all five numbers is 30.

What is the code ?

74658

* 8 + 6 =14
* 5 = 4 + 1
* 7 = 2*4 - 1
* 4 + 6 = 10
* 7+4+6+5+8 = 30

#136 - Mother Age Maths Puzzle

Ramon is 45 years old and his mother Athena is 73 years old.

Can you find out how many years ago, his mother was three times his age?

When Ramon was 14.

Thus, the answer is 31 years ago. Ramon was 14 and Athena was 42.

#137 - Find Ages Riddle

Priyanka and Rubina are having a conversation.

Priyanka: I am definitely not over 30.
Rubina: I am 28 and you are surely 5 years older to me at least.
Priyanka: No, you are at least 29.

You are told that both of them are lying throughout in the conversation. Can you find their respective ages?

We know that both of them were lying in all their statements. Thus we can assume the opposite of what they said:

Priyanka: I am definitely over 30.
Rubina: I am not 28 and you are at most 4 years older to me.
Priyanka: You are at most 28.

Now we can conclude from the first statement that Priyanka is 31 years old at least. From the second and third statement, we can conclude that Rubina is at most 28 years old. Therefore, the possible ages of Priyanka and Rubina can be:

Priyanka: 31, 32, 33, 34, 35, 36...
Rubina: 22, 23, 24, 25, 26, 27...

If we look at the second statement again, we know the difference between their ages is a maximum of 4 years.
Therefore, Priyanka age is 31 years while Rubina age is 27.

#138 - Split Money Pizza Maths Puzzle

Rihana, Peeta, and Logan order a pizza for $10. Out of the three, Rihana and Peeta were quite hungry and ate 6 slices a piece, while Logan had just 2 slices.

Now, they want to split the cost among them fairly but due to the lack of change, they decide to round of the cost to the nearest possible dollar.

Can you find out the fair way which should be used to split the money?

What if the pizza was worth $11?

If we assume that Rihana and Peeta pay the same amount, they can decide with "rock, paper, scissor" to determine who will pay the extra dollar. Any other method may be used as well. Suppose that Rihana pays $1 extra.

In this manner, Rihana pays $5, Peeta pays $4 and Logan pays $2.

If the pizza would have cost $11, this method will then prove to be great because both Rihana and Peeta will pay $5 each and Logan will pay $1. This will keep the offset same as previous. Rihana is paying 6% more, Peeta is paying 15% more and Logan is paying 27% more.

#139 - Buy Maths Chocolate Puzzle

A kid goes to a confectionery and buys three kinds of chocolates. The first one is priced at 5 rupees, second one at 3 rupees and third one at 0.5 rupees.

If he bought 100 chocolates in total, how many pieces do you think he bought of each chocolate?

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

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

Therefore, the two possible answers are
a = 5, b = 11, c = 84
a = 10, b = 2, c = 88

#140 - How Many Animals Maths Puzzle

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

There are a total of 102 animals and 34 of each kind.

Since we know that the number of each animal is equal. Therefore, each cricket, squirrel and spider will be having 18 legs.

Now, 612/18 = 34 of each animal.

Therefore, number of animals in total = 34 * 3 = 102.