1. Correct answer is a (since when you are not given the n values, it is implied that the first value is 1). 3. Correct answer is a (a(n)=-3+4(1-1)=-3). 7. The pattern is to reduce the previous value by 4, thus the 12th term of the sequence is -24 (a(n)=20 - 4(n-1)=20 - 4(12-1)=-24). 8. Missing term is 26 (32+20=52; 52/2=26). 10. Pattern is 625/1=625; 625/5=125; 125/5=25; 25/5=5, thus. the 10th term is 1/3125 (answer a).