Check if you can write an equation relating the term number to the actual value
n1=3
n2=10 = 3+7
n3= 17 = n2+7 = n1+7+7 = n1 +2*7
n4= 24 = n1+3*7
so you will notice a pattern
for the x-th term
n_x =3+(x-1)*7
the 50th term would be n_50 = 3+(50-1) * 7
The right option is (c). The Mean Value Theorem does not apply since f(x) is not differentiable on (-1,8). Because the derivative of f is 2/3 x^(-1/3) which is undefined at x=0.So, that would imply that it is not differentiable along the interval.
The answers is D 21,000because you have to do 60,000x.35=21,000