Math
Five times the difference of twice a number and three, decreased by the sum of this number and eight, equals thirteen.
Math
The ages of a father and son add up to 66. The father's age is the son's age reversed. How old could they be?
Math
Find the four-digit number in which the first digit is one-fourth of the last digit, the second digit is 6 times the first digit, and the third digit is the second digit plus 3.
Math
If you multiply this number by any other number, the answer will always be zero. What number is this?
Math
In an alien land far away, half of 10 is 6. If the same proportion holds true, then what is 1/6th of 30 in this alien land?
