ARITHMETIC PROGRESSION 4

The 1st term of an A.P. is 70 and the common difference is 40. Find the 10th term.

Solution

A₁= 70, d = 40

A_n = A₁ + (n-1)d

A₁₀ = A₁ + (10-1)d

A₁₀ = A₁ + 9d

A₁₀ = 70 + (9x40) [ after substituting A₁= 70, d = 30 as given above]

∴ A₁₀ = 70 + 360

A₁₀ = 430

Hence the 10th term is 430.

  

TRY THIS……………

The 1st term of an A.P. is 60 and the common difference is 43. Find the 7th term.