(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.