JavaScript while循环与布尔变量作业疑问求助

我之前通过视频学了for和while循环的基础结构，比如标准的while循环是这样的：

while(condition is true) {
 //do something
}

但作业里的题目和学的内容脱节，完全不知道怎么下手，导师的回答还更模糊，只能来求助。

问题1：基于布尔变量的while循环实现 #

作业给出了一种用布尔变量控制的while循环写法，要求补全代码：

// Another way to write a while loop is to have a boolean variable 
// where the condition goes and then test every time if you need to
// change the boolean to false.

// Below we have a variable lessThan5 and it is set to true.
// Create a loop that tests if our variable 'j' is less than 5.
// If it is less than 5 then Increment it by 1. If it is not 
// less than 5 then set our lessThan5 variable to be false.
let lessThan5 = true;
let j = 0;

while(lessThan5) {
}

我没学过用布尔变量来控制while循环的写法，作业的指令也说不清楚，不知道怎么写循环体里的内容。

问题2：按指定次数循环的while循环实现 #

作业先给了一个猜数字游戏的示例代码：

// Example of what the number game would look like:
// Couple things to note:
// Math is a built in object in javascript.
// Math.round() will round a decimal number to a whole number.
// Math.random() returns a decimal number between 0 to 1.
// (But not including 1)
function guessNumberGame(guess) {
  let guessing = true;
  let number = Math.round(Math.random() * 100);
  while(guessing) {
    if(guess === number) {
      guessing = false;
    } else {
      guess = Number(prompt("That number didn't work. Try again: "));
    }
  }
}

然后是Problem 3的要求：

// Problem 3
// We will give you a number through the 'num' parameter
// Create a while loop that will loop 'num' amount of times.
// For example if num is 3 then your while loop should loop 3 times
// If num is 20 then the loop should loop 20 times.
// Increment k every loop.
let k = 0;
function keepLooping(num) {

}

我完全看不出这个问题和前面的猜数字示例有什么关联，也不知道怎么写这个循环来达到指定的次数。

之前学习进度一直没问题，现在突然卡在这里，周围也没人提相关疑问，感觉特别困惑。

内容的提问来源于stack exchange，提问作者mosty frug