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

Solution: 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: 120 x 6 x 4= 720 720 x 4=2880 hectares. Let's suppose that each of the four tractors ploughed x hectares a day. Therefore in 5 days they ploughed 5 x 4 x x=20 x x hectares, which equals the area of the whole field, 2880 hectares. So, we get 20x=2880 x=2880 over 20 =144 . Hence, each of the four tractors would plough 144 hectares a day.

Answer 2

Case 1 :
Tractors = 6
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

So, total area of the field = 2880 hec


Case 2:
Tractors = 6 - 2 = 4
Days = 5
Area ploughed by one tractor = ?

Area of the field = 2880 hec

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