in a group of cows and hens , the number of legs are 10 more than twice the number of heads . the number of cows is :
"let no of cows be x , no of hens be y . so heads = x + y legs = 4 x + 2 y now , 4 x + 2 y = 2 ( x + y ) + 10 2 x = 10 x = 5 . answer : a"
subtract(10, const_4)