Question

Sum of 4 consecutive numbers is 312. What is the sum of middle two numbers?​

Answer 1

ans is 312

right ans is 4312

Answer 2

Answer:

Sum of middle two numbers = 156

Step-by-step explanation:

Let the consecutive numbers be

x, (x + 1), (x + 2), (x + 3)

We can solve it in two ways,

Method 1 (Long Process)

Then, according to the Question,

Sum of consecutive numbers = 312

x + (x + 1) + (x + 2) + (x + 3) = 312

x + x + 1 + x + 2 + x + 3 = 312

4x + 6 = 312

4x = 312 - 6

4x = 306

x = 306/4

x = 76.5

Then,

The middle two number are (x + 1) and (x + 2).

So,

x + 1 = 76.5 + 1

= 77.5

x + 2 = 76.5 + 2

= 78.5

Sum = 77.5 + 78.5

Sum = 156

Method 2 (Shortcut)

According to the Question,

Sum of consecutive numbers = 312

x + (x + 1) + (x + 2) + (x + 3) = 312

Since addition is commutative,

x + (x + 3) + (x + 2) + (x + 1) = 312

Since addition is associative,

(x + x + 3) + (x + 2 + x + 1) = 312

(2x + 3) + (2x + 3) = 312

2(2x + 3) = 312

2x + 3 = 312/2

2x + 3 = 156

Now, what is 2x + 3,

It is actually the sum of the middle two numbers.

How?

The middle two number are (x + 1) and (x + 2).

It's Sum = (x + 1) + (x + 2)

= 2x + 3

Hence,

Sum of middle two numbers = 156

Hope it helped you and believing you understood it...All the best