Question

If an AP, if a = -10, n = 6 and a6 = 10, then the value of d is ______​

Answer 1

Ans. - It should be 4.

Step-by-step explanation:

Slv. - By Using A.P. Formula :-

an = a (n - 1)d.

10 = -10 (6-1) d.

10 + 10 = 5d.

20/5 = d.

4 = d.

d = 4.

Hence, the correct answer should be 4.

Answer 2

Given that:

In a AP,

• a = First term = - 10
• n = Number of terms = 6
• a₆ = Sixth term = 10

To Find:

• The value of d (common difference).

We know that:

• aₙ = a + (n - 1)d

Putting all the given values.

ㅤ↠ㅤ10 = - 10 + (6 - 1)d

ㅤ↠ㅤ10 = - 10 + 5d

ㅤ↠ㅤ10 + 10 = 5d

ㅤ↠ㅤ20 = 5d

ㅤ↠ㅤ20/5 = d

ㅤ↠ㅤ4 = d

ㅤ↠ㅤd = 4

Hence,

• The value of d is 4.