Question

find the sum of all two digits positive integers which are divisible by 4​

Answer 1

Answer:

The sum is 1188.

Step-by-step explanation:

We will solve this question through A.P.

Let number of terms = x.

Here,

a = 12 (Since it is the first two digit positive integer divisible by 4)

d = 4

aₓ = 96 (Since it is the last two digit positive integer divisible by 4)

We know,

aₓ = a + (x - 1)d

96 = 12 + (x - 1)4

84/4 = x - 1

21 = x - 1

x = 22

Now,

Sₓ = x/2 [ 2a + (x - 1)d]

Sₓ = 22/2 [ 2(12) + (22-1)4]

Sₓ = 11 [ 24 + 84]

Sₓ = 11 (108)

Sₓ = 1188

You should use 'n' instead of 'x' here :)

If you find any mistake, please let me know!

Hope it helps..