Hello Can someone help me with these math problems?

Translation: consider the following arithmetic succession

2. the common difference is

3. The formula for An is:

4. The value of a21 is:

Preguntas 2-5: Considere la siguiente sucesion aritmetica: 3, 3.25, 3.5, 3.75, .... 2. La diferencia comun es: a. 1/2 b. 1/4 C. 3/4 d. 5/4 3. La formula para an es: a. an = 3 + 0.25(n - 1) b. an = 3 + 0.5(n =1) C. an = 3 + 0.75(n -1) d. an = 3 + 1.25(n - 1) 4. El valor de a2 es: 5 b. 6 C. 7 d. 8