A collection of building blocks is set up into 51 rows. The first row has 124 blocks, and each row after that one has 4 more blocks than the preceding row.

Question

How many blocks are in the 10th row? a.)114 b.)160 c.)214 d.)321 help ASAP!!!!!

Answer 1

This is an arithmetic sequence.

 

a_n = a₁ + (n - 1)d, where a₁ = first term, a_n = nth term, n = number of terms, d = common difference

 

a₁₀ = 124 + (10 - 1)4

a₁₀ = 124 + (9)4

a₁₀ = 124 + 36

a₁₀ =160

 

The tenth row has 160 blocks.