ARITHMETIC PROGRESSION 3

The 1st term of an A.P. is 70 and the common difference is 30. Find the 10th term.

Solution

A₁= 70, d = 30

A_n = A₁ + (n-1)d

A₁₀ = A₁ + (10-1)d

A₁₀ = A₁ + 9d

A₁₀ = 70 + (9x30) [ after substituting A₁= 70, d = 30 as given above]

∴ A₁₀ = 70 + 270

A₁₀ = 340

Hence the 10th term is 340.

TRY THIS……………

The 1st term of an A.P. is 40 and the common difference is 33. Find the 7th term.