In a group of cows and hens, the number of legs are 14 more than twice the number of heads. How many cows are there? | WBCS 2022

In a group of cows and hens,

 the number of legs are 14 more

 than twice the number of heads.

 How many cows are there?

(a) 7
(b) 12
(c) 5
(d) 10

Correct Answer: 7

Solution: 

Let the number of cows are x and 

number of hens are y. 

Each cow has 4 legs and one head
Each hen has 2 legs and one head
So, 
4x+2y=2(x+y)+14
Solving this equation we get, x=7
Therefore number of cows are 7