Question

there are 25 rows and each row has eight more toothpicks than the row above. The top row has 5 toothpicks. How many toothpicks are on the bottom row?

Answer 1

its an AP
a=5
d=8
n=25
last term= a+(n-1)*d

Answer 2

this is an arithmetic sequence... where a = 5 d = 8 and n = 25

us the formula

\[T _{n} = a + (n -1) d\]

just substitute and evaluate to sind the toothpicks in row 25

Answer 3

so the answer is 197?

Answer 4

yes

Answer 5

thank you!