SOLUTION: A number is increased by 50 percent, and then the resulting number is decreased by 40 percent. What was the original number if the final number is eight less than the original?

Algebra ->  Equations -> SOLUTION: A number is increased by 50 percent, and then the resulting number is decreased by 40 percent. What was the original number if the final number is eight less than the original?      Log On


   



Question 476962: A number is increased by 50 percent, and then the resulting number is decreased by 40 percent. What was the original number if the final number is eight less than the original?
Found 2 solutions by josmiceli, lwsshak3:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = original number
given:
+x+%2B+.5x+ is the original number
increased by 50%
+x+%2B+.5x+=+1.5x+
---------------------
+1.5x+-+.4%2A%281.5x%29+ is the resulting number
decreased by 40%
+1.5x+-+.4%2A%281.5x%29+=+1.5x+-+.6x+
+1.5x+-+.6x+=+.9x+
---------------------
+.9x+=+x+-+8+
+.1x+=+8+
+x+=+80+
The original number was 80
check:
Increased by 50% is 120
Decrease this by 40%
120 - .4*120 = 120 - 48
120 - 48 = 72
72 is 8 less than 80
OK

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
A number is increased by 50 percent, and then the resulting number is decreased by 40 percent. What was the original number if the final number is eight less than the original?
**
let x=number
(x+.5x)-.4(x+.5)=x-8
1.5x-.4*1.5x=x-8
1.5x-.6x=x-8
.9x=x-8
.1x=8
x=80
ans:
original number=80