Question

there are 3 students... all 3 invested rs. 20 each to buy a cricket ball.. they went to shop and buyed it from shopkeeper it costs them 60rs (but actually it was of 50) and went away.. after a while shopkeeper decided to took 4rs of those of rs10 extra in his pocket and the rest rs6 to those students 2-2 each...
now the que is.. students got 2-2 each which means they invested 18 each... so
18+18+18=54 ,
as shopkeeper has put 4rs... so 54+4=58....
then where the hell 2rs has gone..?

Answer 1

Case 1:
Each student gave Rs. 20
So total money is 20× 30= Rs.60
But original price is Rs. 50
The shopkeeper made a profit of Rs.(60-50)= Rs 10
Now the shopkeeper kept Rs. 4 with himself and returned Rs.6 (Rs.2 to each student). This means that each student gave Rs.(20-2)=Rs.18
Case 2:
Each student gave Rs. 18
Total money is Rs18×3= Rs.54
But original price is Rs.50
Money left with shopkeeper is
Rs. (54-50)= Rs.4

Explanation: When the shopkeeper returned Rs.6 to the students, he was left with Rs.4. This means that each student contributed Rs.18 and the total money collected was Rs. 54. Hence the shopkeeper was left with Rs. 4 and NOT with Rs. 58. He was left with Rs.4 as each student gave Rs.18. Each student is still left with Rs.2. Observe Case 2 carefully. If you still get any doubts add it in the comments!