posted by jojo .
how often does a leap year occur?
what are al the prime numbers less then 12. what is the eighth multiple of 32? is the last digit of the multiples if 4 odd or even?
what are the six factors of 12?
what are the factors of 16.
two factors of 20 are 1 and 20. what are the four more factors of 20?
what are the factors of 11? what are the factors of 24?