C100DEV MongoDB Overview and Document Model Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  $gte and $lte

  Why it's wrong here

  The $gte (greater than or equal) and $lte (less than or equal) operators would include products with a price of exactly 100 or 200. The requirement is for prices greater than 100 and less than 200, so these operators would incorrectly include boundary values. They are used for inclusive ranges.

• ✗

  $and with $gt

  Why it's wrong here

  Using $and with two separate $gt conditions would be redundant and incorrect for a range. For instance, {price: {$gt: 100, $gt: 200}} would effectively apply only the last condition. The $and operator is used to combine multiple independent conditions, but for a range on the same field, $gt and $lt are combined directly.

• ✗

  $in

  Why it's wrong here

  The $in operator matches any of the values specified in an array. It is used for equality checks against multiple possible values, not for range queries. For example, {price: {$in: [100, 200]}} would match only exactly 100 or 200, not a range.

• ✓

  $gt and $lt

  Why this is correct

  The $gt (greater than) and $lt (less than) operators are used to specify a range condition. By combining them in a query like {price: {$gt: 100, $lt: 200}}, MongoDB returns documents where the price falls strictly between 100 and 200. This is the correct way to express an exclusive range.