Answer:
B
Explanation:
the nth term of an arithmetic progression is
= a₁ + (n - 1)d
a₁ is the first term , d the common difference , n the term number
given a₅ = 0 and a₁₀ = 10
set up 2 simultaneous equations to solve for d and a₁
a₁ + 4d = 0 → (1)
a₁ + 9d = 10 → (2)
subtract (1) from (2) term by term to eliminate a₁
(a₁ - a₁ ) + (9d - 4d) = 10 - 0
0 + 5d = 10
5d = 10 ( divide both sides by 5 )
d = 2
substitute d = 2 into either of the 2 equations and solve for a₁
substituting into (1)
a₁ + 4(2) = 0
a₁ + 8 = 0 ( subtract 8 from both sides )
a₁ = - 8
Then
a₂₀ = - 8 + (19 × 2) = - 8 + 38 = 30