The passage mainly explains

that a small share of causes often produces most results, and how to use that (The passage explains the 80/20 pattern of uneven results and how to use it to choose where to focus.)

According to the passage, what does the 80/20 rule say about causes and effects?

A small part of the causes tends to produce a large part of the effects (The text states 'A small part of the causes tends to produce a large part of the effects'.)

Why does the passage call the rule 'a tool for choosing'?

Because spotting the high-value share lets you aim your effort there (If a small share produces most value, you can 'find that share and protect it': the rule guides where to spend effort.)

In this passage, 'lopsided' most nearly means

uneven, tilted to one side (Set against 'shared out evenly', 'lopsided' means uneven and tilted toward one side.)

The Rule of the Vital Few: Level 3 Reading Comprehension Questions

People often assume that results are shared out evenly: put in twice the work, get twice the reward. In practice, outcomes are frequently lopsided. A small part of the causes tends to produce a large part of the effects. This rough pattern is known as the 80/20 rule, or the Pareto principle.

The numbers are not exact, and they are not magic. The point is only that effort and result are often unequal. A few products may bring in most of a company's sales. A handful of streets may see most of a city's traffic. A short list of tasks may deliver most of what you truly care about, while a long tail of minor tasks adds little.

Seen this way, the rule is a tool for choosing. If a small share of your work produces most of the value, the smart move is to find that share and protect it, rather than treating every task as equal. The lesson is not to do less, but to notice that not all effort counts the same, and to aim your best energy where it matters most.

Comprehension questions