I’ve encountered such things daily in calculating cost factors in the businesses I’ve run and STILL run. . . and the devil, and the profit, is in just such details. An approximate five percent error such as demonstrated by that simple example can BANKRUPT a firm, or cause a Martian probe to CRASH because someone made an unconscious error! Both of those are REAL WORLD examples of just such events. How about the one that required the Hubble Space Telescope to be fitted with “corrective lenses” at the cost of hundreds of millions of dollars, Oleg-hai? Smart people do make stupid mistakes because they don’t check their assumptions. . . or check things they “know!”
The wording of your “dollar more” problem would not exist in accounting, so errors would manifest in a different way. And please lay off the hyperbole (for the second time) . . .
x=bat
y=ball
x+y=110
y=x-100
x+x-100=110
2x-100=110
2x=110+100
2x=210
x=105 bat
x+y=ball
y=x-100
y=105-100
y=5 ball
My first impulse was to do as the writer suggested and assign 100 to the bat and 10 to the ball...’till I worked the math. Boy did I feel stupid. And this is pretty much the extent of my algebra skills...sorry to say!
I was taught about algebraic systems of equations in the eighth grade. How smart do people have to be to retain elementary algebra?