Question

A farming field can be ploughed by 6 tractors in 4 days. When 6 tractors work together, each of them ploughs 120 hectares a day. If two of the tractors were moved to another field, then the remaining 4 tractors could plough the same field in 5 days. How many hectares a day would one tractor plough then?​

Answer 1

Answer:

$\huge \bf\color{navy}144 \: hectares$

Step-by-step explanation:

If each of 6 tractors ploughed 120 hectares a day and they finished the work would be finished in 4 days, then the whole field is:

$\bf \: 120 \times 6 \times 4= 720$

$\bf \: 720 \times 4=2880 \: hectares$

Let's suppose that each of the four tractors ploughed x hectares a day.

$\bf \: Therefore \: in \: 5 \: days \: they \: ploughed$

5x × 4x = 20x hectares, which equals the area of the whole field, 2880 hectares.

$\bf \: So, we \: get \: 20x=2880$

$\bf \: x=2880 \: over \: 20 =144$

Hence, each of the four tractors would plough 144 hectares a day.

$\huge \: \: \: \: \: \: \: \: \: \: \: \bf \color{teal}(or)$

$\bf \: Case \: 1:$

$\bf \: Tractors = 6$

$\bf \: Days = 4$

Area ploughed by one tractor = 120 hec

Area ploughed by all 6 tractors in a day = 6 × 120 = 720 hec

So, area ploughed by the tractors in 4 days = 720 × 4 = 2880 hec

$\bf \: So, \: total \: area \: of \: the \: field \: = \: 2880 \: hec$

$\bf \: Case \: 2:$

$\bf \: Tractors = 6 - 2 = 4$

$\bf \: Days = 5$

$\bf \: Area \: ploughed \: by \: one \: tractor = ?$

$\bf \: Area \: of \: the \: field = 2880\: hec$

$\bf \: So,$

2880 = Area ploughed by one tractor × Total tractors × Total days

2880 = Area ploughed by one tractor × 4 × 5

Area ploughed by one tractor = 2880/20

So, area ploughed by one tractor = 144 hec

Answer 2

Step-by-step explanation:

A farming field can be ploughed by 6 tractors in 4 days. When 6 tractors work together, each of them ploughs 120 hectares a day. If two of the tractors were moved to another field, then the remaining 4 tractors could plough the same field in 5 days. How many hectares a day would one tractor plough then