Answer:
a) {a,b} , {c,d} , {e,f,g},{a , b } = {(a,a) (b,b) (a,b) (b,a)},{c , d } = {(c,c) (d,d) (c,d) (d , c) } ,{e,f,g} = {(e,e) (e,f) (f,e) (e,g) (f,f) (f,g) ( g,e) (g,f)(g,g)}
b) { (a,a)(b,b)(c,c)(c,d)(d,c)(d,d)(e,e)(e,f)(f,e)(f,f)(g,g)
c) {(a,a)(a,b)(b,b)(b,a)(a,c)(c,a)(b,c)(c,b)(c,c)(d,a)(a,d)(b,d)(d,b)(d,c)(c,d)(d,d)(c,c)(c,f)(f,c)(f,f)(c,g)(g,c)(f,g)(g,f)(g,g)
Step-by-step explanation:
a) {a,b} , {c,d} , {e,f,g}
{a , b } = {(a,a) (b,b) (a,b) (b,a)}
{c , d } = {(c,c) (d,d) (c,d) (d , c) }
{e,f,g} = {(e,e) (e,f) (f,e) (e,g) (f,f) (f,g) ( g,e) (g,f) (g,g)}
b) {a} ,{b},{c,d} ,{e,f},{g}
{ (a,a)(b,b)(c,c)(c,d)(d,c)(d,d)(e,e)(e,f)(f,e)(f,f)(g,g)}
c) {a,b,c,d},{e,f,g}
{(a,a)(a,b)(b,b)(b,a)(a,c)(c,a)(b,c)(c,b)(c,c)(d,a)(a,d)(b,d)(d,b)(d,c)(c,d)(d,d)(c,c)(c,f)(f,c)(f,f)(c,g)(g,c)(f,g)(g,f)(g,g)
. Simplifying a bit gives us 
and 
. Raising that number inside the parenthesis to the 15th power gives us 
. Multiplying to finish means that A(t) = $317.22