Question

A finite arithmetic sequence has 12 termsThe last term is 100 and the common difference is 3. What is the first term?

Answer 1

Answer:

67

Step-by-step explanation:

From the question given above, the following data were obtained:

Number of terms (n) = 12

Last term (L) = 100

Common difference (d) = 3

First term (a) =?

We can obtain the first term of the arithmetic sequence as follow:

L = a + (n – 1)d

100 = a + (12 – 1)3

100 = a + (11)3

100 = a + 33

Collect like terms

100 – 33 = a

a = 67

Therefore, the first term of the arithmetic sequence is 67