Find the fourth proportional to the numbers 3, 7, and 9. 

This question was previously asked in
AAI Junior Assistant (Fire Service) Official Paper (Held On: 21 Apr, 2025 Shift 1)
View all AAI Junior Assistant Papers >
  1. 2.33
  2. 3.86
  3. 21
  4. 4.75

Answer (Detailed Solution Below)

Option 3 : 21
Free
ST 1: English
2.6 K Users
20 Questions 20 Marks 25 Mins

Detailed Solution

Download Solution PDF

Given:

Numbers: 3, 7, and 9

Formula used:

If a, b, c are given, then the fourth proportional d is calculated as:

d = (b × c) / a

Calculation:

d = (7 × 9) / 3

⇒ d = 63 / 3

⇒ d = 21

∴ The correct answer is option (3).

Latest AAI Junior Assistant Updates

Last updated on Apr 24, 2025

-> The AAI Junior Assistant Response Sheet 2025 has been out on the official portal for the written examination.

-> AAI has released 168 vacancies for Western Region. Candidates had applied online from 25th February to 24th March 2025.

-> A total number of 152 Vacancies have been announced for the post of Junior Assistant (Fire Service) for Northern Region.

-> Eligible candidates can apply from 4th February 2025 to 5th March 2025. 

-> Candidates who have completed 10th with Diploma or 12th Standard are eligible for this post.

-> The selection process includes a Computer Based Test, Document Verification, Medical Examination (Physical Measurement Test), Driving Test and a Physical Endurance Test.

-> Prepare for the exam with AAI Junior Assistant Previous year papers.

Get Free Access Now
Hot Links: real cash teen patti teen patti cash game mpl teen patti yono teen patti