*A fruit dealer fixes selling price of watermelon juice in such a way that he ends up earning a profit of 30% after paying tax, which is 13% of the cost price. A shopkeeper buys watermelon juice from the dealer and marks up the price by 15% and then adds 25% water to the juice. He then gives a di...

*A fruit dealer fixes selling price of watermelon juice in such a way that he ends up earning a profit of 30% after paying tax, which is 13% of the cost price. A shopkeeper buys watermelon juice from the dealer and marks up the price by 15% and then adds 25% water to the juice. He then gives a di...

There are N questions in an exam. For i=1,2,3....,N, there are 2^(N-i) students who answered i or more questions wrongly. The total number of wrong answers is 8191. Find N.
*{Approach please}*

how many traingles can be formed if all sides have length in natural numbers and perimeter is 24?? guys I need a shortcut for these type of questions..

how many traingles can be formed if all sides have length in natural numbers and perimeter is 24?? guys I need a shortcut for these type of questions..