In an AP, if d = -4, n = 7, an = 4, then a is
a. 6
b. 7
c. 20
d. 28

Solution:

An arithmetic progression (AP) is a sequence where the two consecutive terms have the same common difference. It is obtained by adding the same fixed number to its previous term.

The nth term of an AP is

aₙ = a + (n - 1 )d.

a = first term

aₙ = nth term

d = common difference.

Considering the question, we get the value as,

aₙ = a + (n−1)d.

4 = a + (7 - 1) (-4)

4 = a + 6(-4)

4 = a - 24.

4 + 24 = a

a = 28.

Therefore, a = 28.

✦ Try This: Find the value of n. If a = 10, d = 5, an = 95

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 5

NCERT Exemplar Class 10 Maths Exercise 5.1 Problem 1

In an AP, if d = -4, n = 7, an = 4, then a is, a. 6, b. 7, c. 20, d. 28

Summary:

An arithmetic progression (AP) is a sequence where the two consecutive terms have the same common difference. In an AP, if d = -4, n = 7, an = 4, then a is 28.

☛ Related Questions:

• In an AP, if a = 3.5, d = 0, n = 101, then aₙ will be, a. 0, b. 3.5, c. 103.5, d. 104.5
• The list of numbers - 10, - 6, - 2, 2,... is, a. an AP with d = - 16, b. an AP with d = 4, c. an AP . . . .
• The 11th term of the AP: -5, -5 /2 , 0, 5/ 2 , ...is, a. -20, b. 20, c. -30, d. 30