Question

It takes 8 workers 12 days to build a wall work out how many days it would take 3 workers to complete the same job

Can anyone please help?

Answer 1

Answer: 4.5 days or 4 1/2 days

Step-by-step explanation: We can use cross product property, to solve this. Workers to Days remember that

Answer 2

❍ Question -:

If 8 workers can build a wall in 12 days. How many days will it take 3 workers to build the same wall ?

❍ Step-by-step explanation -:

In this question we are provided that 8 workers can finish a piece of work in 12 days. We are asked to calculate how many days it will take 3 workers to complete the same work.

We can solve this question using two methods :

• Unitary Method
• Method of proportion

`\small \green{ \underline{ \underline{\bf{ Unitary \: Method}}}}`

8 workers can build a wall in 12 days

1 worker can build a wall in 12 × 8 days

3 workers can build a wall in
`(12 × 8)/(3)` = 32 days.

• Hence, If 8 workers can build a wall in 12 days. 3 workers will take 32 days to build the same wall.

`\rule{47mm}{4pt}`

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

Let us assume that 3 workers can build a wall in x days.

`\begin{array}{ cc } \bf{Number \: of \: workers} & \bf{Number \: of \: days} \\ 8 &12 \\ 3&x \end{array}`

Ratio of workers = Inverse ratio of days

`\small\sf{ 8 : 3 :: x : 12}`

Product of mean = Product of extreme

`\rightarrow \small\rm{ 3 * x = 8 * 12}`

`\rightarrow{x \: }\small\sf{ = (8 * 12)/(3) = 32 \: days }`

• Hence, If 8 workers can build a wall in 12 days. 3 workers will take 32 days to build the same wall.

`\rule{73mm}{5pt}`