The Buyer Who is Thief

Once a man steals Rs.100 note from the shop. Later he purchases good of worth Rs.70 from the same shop using that note. The shopkeeper gives back Rs.30 in return. 

How much did shopkeeper loose in the case?


Do you think Rs.130? Or anything else? 

Loss Due To Thief Buyer

What's the case history? 

So did you just answer Rs.130 ? No, that's not correct!

Thief initially steals Rs.100 note. Now imagine instead of Rs.100 he steals goods of worth Rs. 70 + Rs.30 (given by shopkeeper). So eventually, the shopkeeper lost only Rs.100 in the process. 

In other words, the thief exchanges Rs.70 with the goods in the case. He pays for those goods to shopkeeper. So he looses Rs.70 from stolen Rs.100 & gains back via goods.

So eventually, the shopkeeper lost only Rs.100 in the case.

 

The Shopping Challenge

At a stationary shop, shopkeeper sells notebook at Rs.15, Pen at Rs.1 & Eraser at Rs.0.25. You are asked to purchase 100 objects & you are given Rs.100 note. 

So how many notebooks,pens & erasers would you buy?

Shopping Challenge

Here is what should you do! 

Taking The Shopping Challenge

What was the problem?

Let N = number of notebooks, P = number of pens & E = number of erasers.

From the given maths we get 2 equations as,

N + P + E = 100................(1)

15N +1P +E/4=100…....(2)
 
From (1),

P = 100 - N - E

From (2),

60N + 4P + E= 400

60N + 4(100-N-E) + E = 400

60N + 400-4N-4E + E = 400

56N - 3E = 0

56N = 3E

N/E = 3/56

From the ratio, we get, N=3, E=56.

Putting these in equation (1),

We get,

P=41.

So we should buy 56 erasers,41 pens & 3 notebooks to satisfy the given condition. 

Unfair Loss in Savings of Life

On his 20th birthday, Ajay started depositing Rs.500 in his saving box. His brother Vijay used to withdraw Rs.100 from the same box on his birthday every year. On his 60th  birthday, Ajay opens his box & finds only Rs.1000 in it.

How this could be possible?

Ajay & Vijay

This is how it's possible 

Having Birthday On Leap Day

What was looking impossible?

Since Ajay celebrates his birthday on 29th February, he used to deposit Rs.500 in saving box once in 4 years. From age 20 to 60, he celebrated only 10 birthdays saving only 500 x 10 = 5000. 

But Vijay withdrawing Rs.100 every year means he took 100 x 40 = 4000 so far.

That's why only 5000 - 4000 = 1000 left in the box.