Question

Four men working together can dig a ditch in 42 days. They begin the work together but one man works only for half of the days. How much time will be taken to complete the job?

Answer 1

Figure out the fraction of the whole job one man working for one day will complete.

Answer 2

i men =1/168 1/2 men=1/336,

Answer 3

Then, multiply that by 3.5 to get the amount of e job done in one average day by the 4 men.

Answer 4

48 days

Answer 5

That's what I get, too.

Answer 6

4*42/3.5=48

Answer 7

assuming each man works at same rate R

4R = 1/42 --> R = 1/168
it takes 1 man 168 days to dig the ditch

Let the num of days be N
for N/2 days, all four men work together at rate of 1/42
percent of ditch = rate*time
--> N/2 * 1/42 = N/84

for the next N/2 days only 3 men work at a rate of 3/168
--> N/2 * 3/168 = 3N/336 = N/112

all together 1 ditch is dug
add and set equal to 1

--> N/84 + N/112 = 1
\[N = \frac{1}{\frac{1}{84}+\frac{1}{112}}\]
using calculator :)
N = 48

Answer 8

Figuring out the rate is the key to solving these equations.

Answer 9

oh crap i did it the long way :{

Answer 10

But you provided a valuable check on our result, so it is not unappreciated :-)

Answer 11

dumbcow came first so i am giving the medal to him.sry whpalmer4 not giving the medal .becoz u said the easiest way

Answer 12

How exactly did dumbcow come first? Just curious, and don't really care about the medal...

Answer 13

he started answering the question before u came so i said @whpalmer4 .dont mistake me

Answer 14

understood?