( CNN ) -- How powerful is your brain ? Take this informal test , developed by Dr. Abbie F. Salny of Mensa , to see if you 're among the mental elite . Then click here to see how well you did . 1 . What is the 5-digit number in which the first , third and last digits are the same , the first digit is four less than the second , the last is four less than the fourth and the second and fourth are the same ? ( Hint : The sum of all the digits is 33 . ) 2 . Boris Smetana and Karl Smith were world-class chess champions . In one series of matches , each won every game . How ? 3 . Nicole was sure she got the right answer when her botany teacher asked her to pick out the plant that was not a tree from the list below . Which one would you choose ? Peach , plum , walnut , linden , banana . 4 . Six bricklayers can lay 24 bricks in half an hour . How many bricks can 12 bricklayers lay in two hours ? 5 . What is the number that is one more than one-tenth of one-fifth of one-half of 4,000 ? 6 . In a pie-eating contest , Alice was neither first nor last , but she beat Evan . Ben beat Alice . Carol beat Dan who beat Ben . Who was last ? 7 . What letter would logically complete the series below ? A Z B Y C X D W E ? 8 . Jim had a small baseball card collection . All but five were signed , all but five were rookie cards , and all but five were less than 10 years old . What is the minimum number of cards he could have had ? 9 . Start with the number of lives a cat reputedly has , multiply by the number of stitches saved by a stitch in time and add 10 . What is the answer ? 10 . What is the 11-letter word that all smart people spell incorrectly ? Click here for the answers .
Take an informal quiz designed by Mensa to test your brain power . If you get 9 of the 10 questions right , you may be Mensa material . Click here for the answers .