A contractor took a job for his group to do in 20 days. But 12 men did not come up for the job and j

M4maths Previous Puzzles

17 Nov 2016 Original number of man

A contractor took a job for his group to do in 20 days. But 12 men did not come up for the job and job was done by remaining man in 32 days. The original number of man in contractor’s team were?

OPtion

1) 51
2) 66
3) 54
4) 32
5) 65
6) 54
7) 34
8) 36
9) 45
10)40

Solution

Reason -
Let there be x men originally.
X men do the job in 20 days
X-12 men can do the job in 20x/(x-12) days.
Therefore 20x/(x-12) = 32
=> x = 32
Option 4)

Correct Option: 4 Best Solution (9)

SARATCHANDRAN   8 years AGO

let the total number of men initially be N.so N men complete work in 20 days and therefore total work =20*N
similarly (N-12)*32=total work
so 20*N=32*(N-12)
20*N=32*N-384
12*N=384
so N=32

Like? Yes (3) | No (1)  

madanpal vishwakarma    8 years AGO

let us assume that the original number of man is x

so x man can do the job in 20 day's so the one day work of x man is = (1/20)

if 12 man din't come than the one day work by (x-12) people is
=(1/32)

x man in 20 = (x-12) man in 30 day

so

x * 20 =(x-12) *32
20x= 32x -(12*32)

32x-20x =12*32
12x= (12*32)
x=(12*32)/12 =32

So the original number of man is 32 .

Like? Yes (1) | No   

Nitish kesarwani   8 years AGO

X men in group do a work in 20 days
1 days work=20*X
X-12 finish a work in 32 days
hence
X*20= (X-12)*32
so X= 32*12/12 option 4

Like? Yes (3) | No (2)  

Amit kumar singh   8 years AGO

Let original no.=x
Then efficienby of each men=1/20x.
Now,since 12 men did not come then now no. Of men=x-12.
These men finished work in 32 days.So efficiency=1/32(x-12).
Since efficiency of each man will remain same.
So,1/20x=1/32(x-12).
Solve equation you will get x=32.

Like? Yes | No   

Jagriti Priya   8 years AGO

let total men = n
remaining men = n-12
n men done work in 20 days = 20n
(n-12) remaining work completed in 32 days = (n-12)32
20n = (n-12)32
20n = 32n - 384
12n = 384
n = 32.

Like? Yes | No   

DEVANSH SUBNANI   8 years AGO

Let original number of men in contractor's team be x
X:20::32:(x-12)
=>x(x-12)=20*32
=>x(x-12)=640
=>x=32
Option 4)

Like? Yes | No (1)  

Devendra Marghade   8 years AGO

Let x men can complete the work in 20 days, so total work=20x
Also x-12 men can do the same work in 32 days.
So 20x= 32(x-12)
=> 12x= 384 or x=32
Option 4)

Like? Yes | No (1)  

Pragati Rode   8 years AGO

Let the original number of man in contractor's team is x

x men will do work in 20 days
x-12 will do same work in 32 days
inversely proportion

x * 1/32 = (x-12)* 1/20
by solving we get,

20*x = 32(x-12)
12x = 384
x = 32
so option is 4

Like? Yes | No (1)  

arun   8 years AGO

20x/1=(x-12)32/1
20x=32x-384
12x=384
x=32

Like? Yes | No (1)