Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
If 5 workers can build a wall in 12 days, how many days will 10 workers take to build the same wall?
4
6
8
10
6
Since the number of workers doubles (from 5 to 10), the time taken must be halved (12 / 2 = 6).
Number of workers (M1) = 5, Time taken (D1) = 12 days. New number of workers (M2) = 10.
M1тАЛimesD1тАЛ=M2тАЛimesD2тАЛ
Since the number of workers doubles (from 5 to 10), the time taken must be halved (12 / 2 = 6).
Students often wrongly apply direct proportion (5/12 = 10/x), resulting in 24 days, forgetting that workers and time are inversely proportional.
Identify the relationship
Since more workers complete the same task in less time, this is a case of inverse proportion.
M1тАЛimesD1тАЛ=M2тАЛimesD2тАЛ
Substitute the given values
Plug in the known values where M1тАЛ=5, D1тАЛ=12, and M2тАЛ=10 to find D2тАЛ.
5imes12=10imesD2тАЛ
Calculate the final result
Solve for D2тАЛ by dividing the total work capacity by the new number of workers.
D2тАЛ=105imes12тАЛ=6
B is correct because when the number of workers doubles, the time required to complete the same task is reduced by half, resulting in 6 days.
This concept is foundational for 'Pipes and Cisterns' and 'Time, Speed, and Distance' problems where variables are inversely related.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants