Question

find the sum of AP 2,6,10....10 terms​

Answer 1

• Sum of 10 terms of A.P is 200 .

Step-by-step explanation:

To find:-

• Sum of 10 terms of A.P .

Solution:-

Our A.P is 2,6,10

We know,

Sum of n number of A.P = n/2 [2a + (n - 1) d]

In which,

• n is number of terms.
• a is first term.
• d is common difference.

So,

a = 2

d = a₂ - a₁ [a₂ = 6 and a₁ = 2]

= 6 - 2

= 4

Common difference or d = 4

Put d and a in formula :

$\longrightarrow \sf S_{10} = \cfrac{10}{2} \times [2 \times 2(10 - 1) \times 4]$

$\longrightarrow \sf S_{10}=5 \times [4 + (9) \times 4]$

$\longrightarrow \sf S_{10} = 5 \times [4 + 36]$

$\longrightarrow \sf S_{10} = 20 + 180$

$\longrightarrow \sf S_{10} = 200$

Therefore,

Sum of 10 terms of A.P is 200 .