Question

pls help it's urgent

Answer 1

Given that 3 men and 4 boys can do a piece of work in 14 days.

= > 3M + 4B = 1/14  ------ (1)

Given that 4 men and 6 boys can do a piece of work in 10 days.

= > 4M + 6B = 1/10  ----- (2)


On solving (1) * 4, & (2) * 3, we get

12M + 16B = 2/7

12M + 18B = 3/10

------------------------

        2B = 1/70.
 
          B = 1/140.



Therefore 1 boy can complete the work in 140 days.


Hope this helps!

Answer 2

Ratio of men is 3:4 and inversely proportion to number of days to complete the work

Ratio of boys is 4:6 or 2:3 and inversely proportion to number of days to complete the work

Ratio of days to complete the same work is 14:10 or 7:5 and inversely proportion to both number of men and number of boys

If 3 men and 4 boys can do a work in 14 days,
then 3 men and 4 boys will do 1/14 of work in a day.

If 4 men and 6 boys can do a work in 10 days,
then 4 men and 6 boys will do in 1/10 of work in a day.

Let the part of the work done by men be x  and let the part of the work done by boys be y done in a day

Hence
3x +4y=1/14..........(1)
4x+6y=1/10...........(2)

By Solving equations 1 and 2

x=1 / 70
y=1 / 140

Hence 1 man does 1 / 70 of work and 1 boy does 1/140 in a single day.