2 digits number
x <100 because 2digit
x/10 ∈ { 1, 2, 3, 4, 5, 6, 7, 8, 9}
x/3 ∈ {1, 2, 3, 4, 5, 6, 7, 8, 9 }
max number divide by 10 is 90
max number divided by 3 is 99
because we know that numer is divided by 10 so our collections looks like:
{10, 20, 30, 40, 50, 60, 70, 80, 90}
we look from this collections only numbers witch will divided by 3:
30, 60, 90 = this is solutions
a) we need a natural number divided by 3 and 10 lower than 100
b) i need to use lenght of number and what numbers divides them
c) as above
d) baseball, 3 and 10, 3, 30,60,90