ARITHMETIC PROGRESSION 1

The 1st term of an A.P. is 72 and the common difference is 45. Find the 10th term.

Solution

A₁= 72, d = 45

A_n = A₁ + (n-1)d

A₁₀ = A₁ + (10-1)d

A₁₀ = A₁ + 9d

A₁₀ = 72 + (9x45) [ after substituting A₁= 72, d = 45 as given above]

∴ A₁₀ = 72 + 405

A₁₀ = 477

Hence the 10th term is 477.

  

TRY THIS……………

The 1st term of an A.P. is 160 and the common difference is 33. Find the 8th term.