NumericalModerate1.5 marks
4(ii)
The first term of an Arithmetic Progression (A.P.) is 5, the last term is 50 and their sum is 440. Find:
common difference
Topic: Arithmetic progression
Previous-year question practice database
Answer
Exam answer
Given:
First term a = 5 Last term l = 50 Number of terms n = 16
Formula for the nth term of an Arithmetic Progression:
l = a + (n − 1)d
Substitute the given values:
50 = 5 + (16 − 1)d
50 = 5 + 15d
50 − 5 = 15d
45 = 15d
d = 45/15
d = 3
Answer:
Common difference = 3.
Explanation
Use the nth-term formula after obtaining n = 16 in part (a).