pls help me with this:
3. Twenty (20) men can finish the job in 30 days. Twenty five (25) men were hired at the start and 10 quit after 20 days. How many days will it take to finish the job?
a. 27 b. 28 c. 29 d. 30

Question

pls help me with this:
3.	Twenty (20) men can finish the job in 30 days. Twenty five (25) men were hired at the start and 10 quit after 20 days. How many days will it take to finish the job?
a. 27			b. 28			c. 29			d. 30

amistre64 · Answer

what is our unit rate per man?

amistre64 · Answer

in one day, 1/30 of the job is completed by 20 men

1/30 divided by 20 gives us the rate at which one man can do the work per day

anonymous · Answer

1/30 divided by 20 = 1/600

anonymous · Answer

then what happens next? @amistre64

amistre64 · Answer

well, 1 man can do 1/600 of the work in a day

how many men are working to start with?  and for how many days?

anonymous · Answer

im so sorry sir but i really dont know how to do it

amistre64 · Answer

reading the question is all

how many men are working to start with?  and how many days to they work?

amistre64 · Answer

if 1 man can do 1/600 of the work in a day

then x men can do x*1/600 of the work in a day .... and we just multiply that by how ever many days they work to find out how much was done, and therefore how much is left to be done