## Some fish, some dogs and some children are swimming in a bay. There are 40 legs in total, twice as many heads as tails and more dogs than fish.

Some fish, some dogs and some children are swimming in a bay. There are 40 legs in total, twice as many heads as tails and more dogs than fish.

How many fish are in the bay?

Lets look the soluiton step by step.

• Fish hasn’t got any legs. Dogs have 4 legs and a child has 2 legs.
• All of them have heads.
• If we say there are x tails there are 2x heads.

Let’s say a for child, b for dogs c for fish.

• 4b + 2a = 40 (i)
• 2c = a + b       (ii)
• c > b                (iii)

from (i) and (ii)  2b + 4c = 40 ..  in the question said that c > b   and 4b + 2a = 40 .. Now, let’s look the opitons because this riddle have 3 answers.

for b = 2,  c =9,  a = 16

for b = 4,  c = 8, a = 14

for b = 6,  c = 7,  a = 8

## I had \$370.00. My Mom gave \$150.00. My Dad gave \$150.00.

Math Riddle: I had \$370.00. My Mom gave \$150.00. My Dad gave \$150.00. My Aunt and Uncle gave me \$100.00. I had another \$30.00. How much did I have?

This is a so hard riddle. Don’t be quick.  The answer is not \$800. Think about it more times and read again and again.

Can’t you find the correct answer? Lets tell the step by step.

• My Mom gave \$150.00.
• My Aunt and Uncle gave me \$100.00.

If your read again you can see mom, dad, aunt and uncle “gave”… We can’t count this money for I have.

Only we can sum  I had \$370.00 and I had another \$30.00.

## A young man decides to buy a collector’s baseball card. He pays \$60 for it.

Riddle: A young man decides to buy a collector’s baseball card. He pays \$60 for it. After a month, the value of the card has increased to \$70 and he decides to sell it. But already a few days later he regrets his decision to sell the collector’s item, and he buys it again. Unfortunately he has to pay \$80 to get it back, so he loses \$10. After a year of owning the baseball card, he finally decides to sell it for \$100. What is his overall profit?

This riddle seems very easy at first, but you need to be careful solving it or you might think you have found the answer correct and disappoint when you realize you could not find it. The most important thing you need to be careful is that the riddle asks for the overall profit not net profit. When he buys the card for \$60 and sells it for \$70, his profit here is \$10. Later, he again buys it for \$80 and after a while he again sells it for \$100, his profit from this sale is \$20. Therefore, his overall profit is the addition of his first and last profits and the answer is \$30.

The answer is:  \$30.00. Overall profit, not net profit!

## Parker has a part-time job picking apples.

Parker has a part-time job picking apples. Let the random variable A represent the number of baskets of apples picked each day. The distribution of A has mean 4.5 baskets and standard deviation 1.3 baskets. Parker is paid \$65 per day plus \$5 per basket. What are the mean μ and standard deviation σ of Parker’s daily pay?

A=μ=\$87.50 and σ=\$71.50

B=μ=\$87.50 and σ=\$6.50

C=μ=\$22.50 and σ=\$6.50

D=μ=\$87.50 and σ=\$1.30

E=μ=\$22.50 and σ=\$71.50

Number of baskets of apples picked each day by Parker = A

Mean of A = 4.5 baskets

Daily payment received by Parker = US\$ 65 + US\$ 5 per basket

Let’s find out the mean and standard deviation of Parker’s daily pay:

Daily payment received by Parker = US\$ 65 + US\$ 5 per basket

Daily payment mean received by Parker = 65 + 5 * 4.5

Daily payment mean received by Parker = 87.5

Standard deviation in US\$ = 1.3 * 5

Standard deviation in US\$ = 6.5

The correct answer is B. μ = US\$87.50 and σ = US\$6.50

## Where are my smart friends? Riddle

Riddle: Where are my smart friends? I had \$3.00. My mom gave me \$10.00. My dad gave me \$30.00. My aunt and uncle gave me \$100.00. I had another \$5.00. How much did I have?

This riddle is about money, Think about a boy had some dollars from family. At the end, we must calculate the boy how much money had? The answer is not 148 dollar.

Solution:

My mom gave me \$10.00.

My aunt and uncle gave me \$100.00.

If you noticed that, all tense at past. So, we must calculate only “I had \$3.00.”   and  “I had another \$5.00.”.

If we sum this money 3 dollars and 5 dollars, The boy had onyl 8 dollars.

## Arianna is deciding between two different movie streaming sites to subscribe to.

Arianna is deciding between two different movie streaming sites to subscribe to.

Plan A costs \$32 per month plus \$1 per movie watched. Plan B costs \$7 per month plus \$2 per movie watched. Let A represent the monthly cost of Plan A if Arianna watches x per month, and let B represent the monthly cost of Plan B if Arianna watches x movies per month. Write an equation for each situation, in terms of x, and determine the number of monthly movies watched, x, that would make the two plans have an equal monthly cost.

Solution:

For the first plan:  cost 32\$ + \$1 per movie == 1.x + \$32

For the second plan: cost \$7 + \$2 pe movie == 2.x + \$7

For the two plans have an equal monthly cost.:

x + 32 = 2x + 7

x = 25.

So,  if Arianna watch 25 movie monthly, cost is equal for the two plans.

## An apprentice baker made 40 liters of 60% sugar syrup instead of 40 liters of 45% sugar syrup.

An apprentice baker made 40 liters of 60% sugar syrup instead of 40 liters of 45% sugar syrup.

How much syrup should she drain and replace with distilled water so that the resulting solution is 40 liters of 45% syrup?

Solution:

Firstly, lets find the only syrup. 40 liters of 60% sugar syrup == 26 liters syrup and 16 litres water.

For the 45% syrup, we must add some woter. We have 26 liters syrup.

If we have a 45% sugar syrup, we need 31.7 liters water for 26 liters syrup.

At the begining, we had 16 liters water. So 31.7 – 16 = 15.6 liters added water.