If 12 men and 13 boys can earn $3,720 in 3 days, while 5 men and 6 boys can earn $2,700 dollars in 5 days, how long will it take for 3 men and 4 boys to earn $2,380?

Bonus Question: Can you solve this without working out how much does a man or a boy earn per day?

M=pay for 1 day for a man

B=pay for 1 day for a boy

so 1 - 12M + 13B = 3720/3 = 1240

and 2 - 5M + 6B = 2700/5 = 540

3 - (1-2) 7M + 7B = 700 hence

4 - M + B = 100

5 - 1 - 9*4 gives 3M + 4B = 340

so to earn 2380 takes 2380/340 = 7 days (without working out the daily rate for man or boy)

Posted by Stefan Petszaft on 2006-09-14 13:54:27