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JEE Main Mathematics question

MathematicsPermutations and CombinationsJEE Main

A person forgets his -digit ATM pin code. But he remembers that in the code all the digits are different, the greatest digit is and the sum of the first two digits is equal to the sum of the last two digits. Then the maximum number of trials necessary to obtain the correct code is

Answer: 72

Solution

The digits come from and include ; we need two disjoint pairs with equal sums, one pair containing . The pairs are: sum : with ; sum : with ; sum : with

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Question ID VK-020896