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The 20th term of an arithmetic progression 1,5,9,13......​

User ChevCast
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1 Answer

3 votes

Answer:

a₂₀ = 77

Explanation:

There is a common difference between consecutive terms , that is

5 - 1 = 9 - 5 = 13 - 9 = 4

This indicates the sequence is arithmetic with nth term


a_(n) = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 1 and d = 4 , then

a₂₀ = 1 + (19 × 4) = 1 + 76 = 77

User Kingshuk Deb
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