my teacher isnt teaching well i need help learning how to do this. please include steps if possible. thank u :)

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Is the square root of 4 plus the square root of 16 rational?

Jim had 3,067.48 in his checking account he wrote a check to pay for two airplane tickets. his account now has 1,845.24.