Question

The sum of 10 terms of an AP: 50, 46, 42, ... is ________.​

Answer 1

Answer:

In the given problem, we need to find the sum of terms for different arithmetic progressions. So, here we use the following formula for the sum of n terms of an A.P.,

Sn=n2[2a+(n-1)d]

Where a = first term for the given A.P.

d = common difference of the given A.P

n = number of terms

50, 46, 42, ... to 10 terms

Common difference of the A.P. (d)

=a2-a1

= 46 - 50

= -4

Number of terms (n) = 10

First term for the given A.P. (a) = 50

So using the formula we get

S10=102[2(50)+(10-1)(-4)]

= (5)[100 + (9)(-4)]

= (5)[100 - 36]

= (5)[64]

= 320

Therefore the sum of first 10 terms for the given A.P is 320

Answer 2

Answer:

320

Step-by-step explanation:

for explanation see the image above

hope it is helpful