Question

A farmer has enough food to feed 40 animals in his cattle for 4 days. How long would the food last if there were 10 more animals in his cattle?

Answer 1

40 cattle can feed for 4 days
if there were 10 more cattle, number of cattle = 40+10 = 50
let number of days they can feed = x

(note: since number of days the cattle can feed is inversely proportional to the number of cattle,
no. of cattle × no. of days = constant
⇒ 40×4 = 50×x
⇒ 50x = 160
⇒ x = 160/50 = 3.2 days

His food would last for 3.2 days if he had 10 more cattle.

Answer 2

Answer:

3.2 days

Step-By-Step Explanation:

If the number of animals increases, then it will take fewer days to last.

Then the two quantities are in inverse proportions.

Let the required number of days be p.

$\because x_1y_1 = x_2y_2$

Where,

$x_1 = 40, \: y_1 = 4, \: x_2 = 50$ and $y_2 = p$ (let)

=> 40 × 4 = 50 × p

=> 160 = 50p

=> p = 160/50

=> p = 3.2

Hence the required number of days = 3.2