Question

A merchant purchased a number of bulls and horses for 1770 dollars. He pays 31 dollars for each bull and 21 dollars for each horse. Find the number of bulls and horses

Answer 1

Answer:

51 Bulls and 9 horses

Step-by-step explanation:

One bull costs 31 doller

One horse costs 21 dollers.

Let the number of horses = Y

and number of bulls = X

∴ 31X + 21Y = 1770 .... where X and Y are natural numbers.

Assume only bulls are bought,

1770/31 = 57 + 3/31

∴ 3 dollers will remain, if only bulls are bought.

To add horses, we must devide subtrat 21Y from 1770, such that, 21Y - 3 must be devisible by 31

21 * 9 = 189 = 31*6 + 3

∴ If there are 9 horses, cost of horses = 189

1770-189 = 1581

1581 / 31 = 51

∴ Number of bulls = 51

Number of horses = 9