If 3men with 4 boys earn rs.2700 in 4 days and 2 man with 3 boys earn rs.1900 in same time , in what time wil

4 men and 4 boys earn rs.8000? please explain the sum and show the solution.

3m + 4b = 2700 / 4 per day
3m + 4b = 675 per day

2m + 3b = 1900 / 4 per day
2m + 3b = 475 per day

Two equations and 2 unknown ... solve for m and b

3m + 4b = 675
m = (675 - 4b) / 3

. . . sub this value into the other equation

2m + 3b = 475
2 * (675 - 4b) / 3 + 3b = 475
(1350 - 8b) / 3 + 9b / 3 = 475
1350 - 8b + 9b = 1425
b = 75 per day

2m + 3 * 75 = 475
2m = 250
m = 125 per day

4m + 4b
4 * 75 + 4 * 125 = 800 per day

8000 / 800 = 10 days <=====

"m " and "b" the amount of money earned by each in one day

Report Abuse

Let the salary given for a single man's work on a day be M.
The salary given for a boy for one day's work be B.
Therefore, (3*M+4*B)*4= 2700
(ie) 12M+16B=2700
Also, (2*M+3*B)*4= 1900
(ie) 8M+12B= 1900
Solving the above two equations,
B=75
M=125
Now we have to find the no of days for 4 men and 4 boys to get 8000 rupees. let the no of days be assumed as x.
therefore, (4M+4B)*x= 8000
(ie) (4*125+4*75)*x= 8000
(ie) 800*x= 8000
(ie) x= 10 days

I'm guessing all men make one amount of money per hour & all boys make a second amount. M = amount men make per day, B = amount boys make per day

4 days * (3M + 4B) = 2700
so 12M + 16B = 2700

4 days * (2M + 3B) = 1900
so 8M + 12B = 1900

So now you have to solve the two simultanious equations. Multiply the second one by 1.5, then each will have 12M & you can subtract one from the other to eliminate M.

1.5*(8M + 12B) = 1.5*1900
12M + 18B = 2850

Now subtract the second equation from the first

12M + 16B = 2700
-
12M + 18B = 2850