Answer:
a₂₀ = 60
Step-by-step explanation:
Given :-
a₃ = 9
a₈ = 24
To find :-
a₂₀
Solving :-
Expand the given values.
a + 2d = 9 -(1)
a + 7d = 24 -(2)
Now subtract (1) from (2).
=> 5d = 15
=> d = 3
a = 9 - 2d
a = 9 - 6
a = 3
Final answer :-
a₂₀
= a + 19d
= 3 + 19(3)
= 3+ 57
= 60
a₂₀ = 60
