Picking the right checkout line at the grocery store is always gamble, but one thing is certain: if you have a small number of items, the express checkout line is the best choice, right? Well, maybe not. When you do the math, it turns out the shortest line might be the fastest, even if the shoppers ahead of you have full carts. Math teacher Dan Meyer set out to figure out the answer to the question we face every time we go grocery shopping: All other things being equal, which is the fastest, the line with more people buying fewer items, or the shorter line of people buying a larger number of items? While his answer is a little complicated for us non-math people, the most interesting finding — backed up by the manager at his local supermarket — is that the express lane isn't necessarily the faster choice.
It turns out every additional person in line adds an extra 48 seconds to the length of time you'll be in line, while every additional item only adds 2.8 seconds. To put it another way: "you'd rather add 17 more items to the line than one extra person!"
I'll be giving this technique a try, and if it doesn't work out, at least I can curse Dan Meyer instead of my own bad judgement when it comes to choosing lines.
Anjali is a former private chef who is currently pursuing a graduate degree in nutrition, with plans to become a registered dietitian. She lives in Los Angeles. You can read more of her health-focused writing at Eat Your Greens.
Read more from Anjali »