Question

if 80 men can do a piece of work in 10 days, in how days can 40 men do the same piece of work

Answer 1

Hey,sup!


If 80 man can do a piece of work in 10 days.
Then 40 men will take double time to do the work = 10*2 = 20 days.
If the efficiency is reduced in half then the time taken will be double.

Hope it helps.

Answer 2

✯ Question -:

If 80 men can do a piece of work in 10 days. In how many days 40 men can do the same piece of work?

✯ Explanation -:

In this question we are given that 80 men can do a piece of work in 10 days and we are asked to calculate how many days 40 men will take to complete the work.

There are two methods to solve this question

• Unitary Method
• Method of proportion

$\small \pink{ \underline{\underline{\bf{ \pink{ Unitary \: Method}}}}}$

80 men can do a piece of work in 10 days

1 men can do a piece of work in 80 × 10 days

40 men can do a piece of work in $\dfrac{80 × 10}{40}$ = 20 days

Hence, 80 men can do a piece of work in 10 days.40 men can do a piece of work in 20 days.

$\pink{\rule{40mm}{4pt}}$

$\small \orange{ \underline{ \underline{\bf{ Method \: of \: proportion}}}}$

Let us assume that 40 men can do a piece of work in x days

$\begin{array}{cc} \bf{Number \: of \: men }& \bf{Number \: of \: days} \\ 80&10 \\ 40&x\end{array}$

80 : 40 :: x : 10

$\small\boxed{ \rm{ Product \: of \: extreme = Product \: of \: mean}}$

→ 80 × 10 = 40 × x

→ $\dfrac{80 × 10}{40}$ = x

→ x = 20 days

Hence, 80 men can do a piece of work in 10 days.40 men can do a piece of work in 20 days.

$\orange {\rule{40mm}{4pt}}$

$\rule{71mm}{4pt}$