Choose the sentence that has the correct preposition in it:

Radha will not be able to reach within half an hour.

The correct answer is Option (4) → Radha will not be able to reach within half an hour.

Other Options:

• They will return with fifteen minutes.

  • Incorrect. The correct preposition for expressing a time limit is "within" or "in".

  • Correction: They will return within fifteen minutes (or in fifteen minutes).

• The students came onto the classroom.

  • Incorrect. The preposition "onto" implies moving to the top surface of something. The correct preposition for entering an enclosed space is "into".

  • Correction: The students came into the classroom.

• Susheel works on the office every weekend.

  • Incorrect. The preposition "on" refers to a surface or a schedule/topic. The correct preposition for working inside a building is "in" or "at".

  • Correction: Susheel works in the office every weekend.