Question

The common difference, d, in an arithmetic sequence whose fourth

term is 16 and whose seventh term is 31.

Answer 1

Answer: 5

Explanation:

Arimethic progression

An=a1+(n-1)d

An= nth term

A1= first term

N= nth position

D= common difference

For the 4th term=16

A4=a1+(n-1)d

16=a1+(4-1)d

16=a1+3d......equation 1

For the 7th term=31

A7=a1+(n-1)d

31=a1+(7-1)d

31=a1+6d.........equation 2

Subtract equation 1 from 2

31=a1+6d

16=a1+3d

15=3d

D=15/3

D=5

Common difference is 5