Question

In a zoo, the ratio of the horses to the zebras was 3:4. when one new horse is added to the group the ratio of the horses to the zebras becomes 4:5. how many horses and how many zebras are there in the zoo now?

Answer 1

The answer is given below :

Let us consider that the ratio of horses to zebras is x : y.

Given that,

x : y = 3 : 4

=> x/y = 3/4

=> 4x = 3y

=> x = 3y/4 .....(i)

and

when 1 horse is added, the condition refers to

(x + 1) : y = 4 : 5

=> 5x + 5 = 4y

=> x = (4y - 5)/5 .....(ii)

Now, equating (i) and (ii), we get

3y/4 = (4y - 5)/5

=> 15y = 16y - 20

=> y = 20

So, from (i), when y = 20,

x = (3 × 20)/4 = 15

Therefore, there are 15 horses and 20 zebras in the zoo.

If 1 horse is added, number of horses be 16.

Thank you for your question.

Answer 2

heya mate here is your answer

Let is consider the ratio of horse to zebra as a:b

then....,, a:b = 3:4

then, 4a = 3b

then, a = 3b/4 _______ (1)


when one more horse is added

ratio is 4:5

then , ( a+1 ) : (b) = 4 : 5

then, 5a + 5= 4b

a = (4b-5) /5 _________ (2)

frm 1 and 2

3b/4 = (4b-5)/5

15b = 16b - 20

-b = -20

b=20

substitute b in 1

=> a = 3b/4 = (3×20)/4 = 15

therefore

number of horses = a+1 = 15+1 =16

numbet of zebra = b = 20


thanks