Question

Divide 700 into two parts such that 40% of one part exceeds 60% of the other by 80.

Answer 1

Let the two parts be x and y respectively.
Given x +y =700. (equation no. 1)

And. 40%x - 60%y = 80.
( 40/100)x - (60/100)y =80.
Taking lcm (40x-60y)/100=80.
40x-60y= 80*100=8000
We can also write it as,
2x-3y=400. (Equation no. 2)
x+y =700. (Equation no. 1)
Multiplying equation 1 by 2 and subtracting it from equation 2.we get
2x-3y=400.
- 2x -2y =-1400.

We get y = 200. Putting y in equation 1 we get x = 500.
Hope this helps