Many students applied for a technical job for a month(April) but only two among them successfully completed the technical rounds. It was time for the final Interview. The interviewer asked both the students whether they would like to have 10 crores rupees for the month or, Re. 1 on day 1, Rs. 2 on day 2, Rs. 4 on day 3 , doubling up everyday till the last day of the month.
Student 1 chose 10 crore rupees. Student 2 chose the other option.
Which student made a better choice and how much was the profit?
Solution: Student 2 made a better choice.
Explanation: Student 1 chose 10 crore rupees. Congratulations to that student! It is a lot of money but about 97.4 crore rupees lesser than what student 2 had opted for.
Student 2 will get Re. 1 on day 1, Rs. 2 on day 2, Rs. 4 on day 3 ….The amount sequence is a geometric progression – 1,2,4,8,16,…..and so on.
Total no. of terms = 30 (April has 30 days)
G.P. summation formula for n terms having first term a and common ratio r : a( (r^n) -1 ) / (r-1)
Here a= 1 , r=2, n=30
Sum = (2^30 -1)/(2-1) = 1073741823
Profit = 1073741823 – 10,00,00,000 = 97,37,41,823
This puzzle is contributed by Feroz Baig. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
- Puzzle 1 | (How to Measure 45 minutes using two identical wires?)
- Puzzle 2 | (Find ages of daughters)
- Puzzle 3 | (Calculate total distance travelled by bee)
- Puzzle 4 | (Pay an employee using a 7 units gold rod?)
- Puzzle 13 | (100 Prisoners with Red/Black Hats)
- Puzzle 5 | (Finding the Injection for Anesthesia)
- Puzzle 6 | (Monty Hall problem)
- Puzzle 7 | (3 Bulbs and 3 Switches)
- Puzzle 8 | (Find the Jar with contaminated pills)
- Puzzle 9 | (Find the fastest 3 horses)
- Puzzle 10 | (A Man with Medical Condition and 2 Pills)
- Puzzle 11 | (1000 Coins and 10 Bags)
- Puzzle 12 | (Maximize probability of White Ball)
- Puzzle 14 | (Strategy for a 2 Player Coin Game)
- Puzzle 15 | (Camel and Banana Puzzle)