Question

The sum of four numbers is 1,320. The sum of three of the numbers is 40% more than the other number, x. What is the value of x ?​

Answer 1

Since the numbers are not consecutive natural numbers, how about if I let the 4 numbers be a, b, c, and d?

The sum is given to be 1320.

a + b + c + d =1320...I will call this the first equation.

Can I then say that the second equation is b + c + d = 0.4a + a? Yes, I can do this.

Simplifying my second equation,

I get b + c + d = 1.4a.

Plugging this into my first equation, I get

a +1.4a =1320

2.4a =1320

So, a =1320/(2.4) =550.

Answer: 550

Answer 2

550

Explanation:

We aren't given that they are consecutive so lets just pretend the numbers are x, y, z , and r.

We are given x+y+z+r=1320

We are also given that y+z+r=.4x+x

Simplifying my second equation gives us y+z+r=1.4x. I'm going to plug this into first equation giving me

x+1.4x=1320

2.4x=1320

So x=1320/2.4=550