Question

A tank is being filled with water at a rate of 5.5 gallons per

minute. Write the first five terms of the arithmetic sequence
being represented after each minute if the tank started with
10 gallons of water.

Answer 1

• First term=a=10
• common difference a=5.5

General formula

• a_n=a+(n-1)d
• a_n=10+(n-1)5.5

So

• a_1=10
• a_2=10+5.5=15.5
• a_3=10+11=21
• a_4=10+16.5=26.5
• a_5=10+22=32
• a_6=10+27.5=37.5

Answer 2

Arithmetic sqaure: a + (n-1) * d

where "a" is the first term, "d" is the common difference

Here given:

a = 10 gallons

d = 5.5 gallons

• nth term: 10 + (n-1) * 5.5

Solve for first 5 terms:

10 + (1-1) * 5.5 = 10

10 + (2-1) * 5.5 = 15.5

10 + (3-1) * 5.5 = 21

10 + (4-1) * 5.5 = 26.5

10 + (5-1) * 5.5 = 32

first five terms: 10, 15.5, 21, 26.5, 32