Question

72 men can build a wall 280 m long in 42 days.The number of persons who would take 36 days to build a similar wall of length 100m will be?​

Answer 1

Answer:

M2=30

Step-by-step explanation:

We know that: m1d1h1/w1=m2d2h2/w2

h1=h2 (as they are doing the work in same number of hours per day)

m1d1/w1=m2d2/w2

72×42/280=m2×36/100

84/280=m2/100

8400=280m2

m2=30

30 members will do the work

Answer 2

Let us make a mathematical problem with the help of the given quantities:

We assume:

• Number of men = M
• Length of wall = L
• Time in days = D

M L D

72 280 42

? 100 36

Here, M is directly proportional to L as if number of men increases, the length of building a wall will increase.

Also, M is inversely proportional to D as if number of men increases, number of people required to complete a work will decrease.

∴ the required number of men

= 72 * 100/280 * 42/36

= 30

∴ 30 men would take 36 days to build a wall of length 100 m.