Help please asap my teacher if just giving it to us

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).

Mariano delivers newspaper. he always puts 3/4 of his weekly earnings in his savings account and then divides the rest equally into 3 piggy banks for spending at the snack shop, the arcade and the subway

Find the cube roots of 8i. write the answer in a + bi