Question

100 cows can graze a field in 15 days and 60 cows can graze it in 30 days. how many cows are needed to graze it completely in 10 days ?

Answer 1

15*100=1500

60*30=1800

300 -15 days

20 - 1day

1200+10*20=1400

For 10days means 1400/10=140cows

Answer 2

Answer:

140

Step-by-step explanation:

Suppose $x =$ quantity of grass One cow may graze for an entire day.

Suppose $y =$ pace of grass growth each day

Suppose  $z =$ how much grass there was when the field first opened

A pasture can be completely grazed by 100 cows in 15 days, as the idiom goes.

$15 * 100 * x = z + 15 * y$

The entire field may reportedly be grazed by 60 cows in 30 days.

$30 * 60 * x = z + 30 * y$

(In other words, the entire amount of initial grass plus the amount of grass growth equals the amount of grass consumed by cows.)

Thus, a set of equations exist.

$1500x = z + 15y\\1800x = z + 30y$

Sub. "opinion" for $300x = 15y$,

that states $20x = y$

replace $20x$ for $y$ in 1 eq.

$1500x = z + 15(20x)1500x = z + 300x1200x = z$

Y and z expressions in terms of x are now available.

Let's put the query in writing. Over the period of 10 days, how many cows (c) are needed to graze the entire field?

$10 * c * x = z + 10 * y$

Change the values to $y = 20x$ & $z = 1200x$

$10 * c * x = 1200 x + 10 * 20x10x * c = 1200x + 200x10x * c = 1400xSolve for c.c = 1400x/10xc = 140$

As a result, the area must be grazed by 140 cows in just 10 days.

The fact that the grass grows while the cows eat it makes the situation more challenging.

#SPJ3

https://brainly.in/question/5878718