Question

I am getting the answer 177, how am I going about this wrong?

Answer 1

This is an arithmetic sequence with

first term = a = 12
common difference = d = 11

so the nth term is equal to `12 + (n-1)*11`

Answer 2

how tall will the plant be in 15 days? we answer this question by plugging in n = 15

12 + (n-1)*11 = 12 + (15-1)*11 = 166

Answer 3

in 15 days, the plant will be 166 mm tall