Answer:
The food will last for 10 days
Explanation:
Proportions
The amount of food the farmer needs to feed his animals is proportional to the number of animals and to the number of days they are fed.
This can be written as:
Food=k*N*D
Where k is a constant, N is the number of animals and D is the number of days.
We know that the farmer has enough food to feed N=50 animals for D=15 days, thus:
Food=k*50*15=750k
If the same amount of food is used for 50+25=75 animals, then:
750k=k*75*D
Simplifying:
750=75*D
Dividing by 75:
D=10
The food will last for 10 days