# Amateur Mathematicians Solve Real-World “Problems”

Procrastination, wardrobe malfunctions, understanding women: mathematicians have devised equations to solve these and other, similarly important everyday problems.

## Equations for Everyday Life

When high school math teachers talked about the practical applications of math, they probably weren’t thinking about the equation 0 = NP(20C + B)/75. According to the British tabloid The Sun, the formula allegedly tells a woman if she’s revealing too much cleavage.

Here’s how they explain the formula: “To figure out the naughtiness rating (0), you times the number of nipples exposed, from zero to two or expressed as fractions of nipple shown (N) with the percentage of exposed frontal surface area (P). The sum in brackets is 20 multiplied by the cup size (C), where A cup is one, B is two, C is three and D or above is five. Add that figure to B, the bust measurement in inches. Then divide your answer by 75. Any score higher than 100 is counted as obscene.”

Another formula, U = EV/ID, helps explain why people procrastinate, according to the Daily Telegraph.

“The ‘U’ stands for utility, or the desire to complete a given task,” the paper says. “It is equal to the product of E, the expectation of success, and V the value of completion, divided by the product of I, the immediacy of the task, and D, the personal sensitivity to delay.”

Piers Steel, a University of Calgary psychology professor, developed the formula. Approximately 20 percent of people are chronic procrastinators, he said. It’s a growing problem, though, with more jobs where people set their own schedules.

Students at California Technical University and Harvard have solved the question of whether to wait for a bus or walk. In almost every circumstance, it’s best to wait, say Justin Chen, Scott Kominers and Robert Sinnott. Their formula looks like this:

d d

— < tb + —

vw vb

The left fraction represents walking, and the second half of the equation represents the amount of time it would take to ride the bus. The exceptions to the equation are when the buses are spaced more than an hour apart and your destination is less than a kilometer away, the authors say.

Another equation, this one of anonymous origin, seeks, tongue in cheek, to prove mathematically that girls are evil. The proof says girls “require time and money” and, as we all know that time is money, we’re left with “Girls = money * money = (money)2.” Money, it goes on to say, is the “square root of all evil,” so girls = evil.

Here’s how they explain the formula: “To figure out the naughtiness rating (0), you times the number of nipples exposed, from zero to two or expressed as fractions of nipple shown (N) with the percentage of exposed frontal surface area (P). The sum in brackets is 20 multiplied by the cup size (C), where A cup is one, B is two, C is three and D or above is five. Add that figure to B, the bust measurement in inches. Then divide your answer by 75. Any score higher than 100 is counted as obscene.”

Another formula, U = EV/ID, helps explain why people procrastinate, according to the Daily Telegraph.

“The ‘U’ stands for utility, or the desire to complete a given task,” the paper says. “It is equal to the product of E, the expectation of success, and V the value of completion, divided by the product of I, the immediacy of the task, and D, the personal sensitivity to delay.”

Piers Steel, a University of Calgary psychology professor, developed the formula. Approximately 20 percent of people are chronic procrastinators, he said. It’s a growing problem, though, with more jobs where people set their own schedules.

Students at California Technical University and Harvard have solved the question of whether to wait for a bus or walk. In almost every circumstance, it’s best to wait, say Justin Chen, Scott Kominers and Robert Sinnott. Their formula looks like this:

d d

— < tb + —

vw vb

The left fraction represents walking, and the second half of the equation represents the amount of time it would take to ride the bus. The exceptions to the equation are when the buses are spaced more than an hour apart and your destination is less than a kilometer away, the authors say.

Another equation, this one of anonymous origin, seeks, tongue in cheek, to prove mathematically that girls are evil. The proof says girls “require time and money” and, as we all know that time is money, we’re left with “Girls = money * money = (money)2.” Money, it goes on to say, is the “square root of all evil,” so girls = evil.

## Opinion & Analysis: Computing the usefulness of such equations

Jacob Aron, author of the blog Just a Theory, pointed out a problem with the Sun’s boobline equation.

“It’s this: if N is zero, then O will be zero, because anything multiplied by zero is zero. In other words, if no nipples are shown then the “naughtiness rating” will always be zero! Hardly scandalising, I think you’ll agree,” wrote Aron, who studied mathematics at the University of Bristol.

In contrast, Paul Simister, author of the blog Business Coaching, found Professor Steel’s procrastination equation useful. It helps, Simister argues, by putting things in perspective.

“First, if you have a low expectation of success in a task, don’t do it. Find someone else who is better able to do it,” Simister said, adding, “Second, if the task is not worth paying someone else, and you are unlikely to do it well, then don’t bother wasting your time. In fact, even if you can do it well and the value is low, don’t bother. Why set yourself up for a task you may procrastinate on?”

“It’s this: if N is zero, then O will be zero, because anything multiplied by zero is zero. In other words, if no nipples are shown then the “naughtiness rating” will always be zero! Hardly scandalising, I think you’ll agree,” wrote Aron, who studied mathematics at the University of Bristol.

In contrast, Paul Simister, author of the blog Business Coaching, found Professor Steel’s procrastination equation useful. It helps, Simister argues, by putting things in perspective.

“First, if you have a low expectation of success in a task, don’t do it. Find someone else who is better able to do it,” Simister said, adding, “Second, if the task is not worth paying someone else, and you are unlikely to do it well, then don’t bother wasting your time. In fact, even if you can do it well and the value is low, don’t bother. Why set yourself up for a task you may procrastinate on?”

## Reference: Mathematics guides

FindingDulcinea has a variety of guides to help you learn about different areas of mathematics, from elementary school math to high school pre-calculus.