Respuesta :
Answer:
140 cows.
Step-by-step explanation:
Let the number of cows in the herd be x. Then:
x - 1/2x - 1/4x - 1/5 x = 7
The LCD of 2, 4 and 5 is 20 so we have
20x/20 - 10x/20 - 5x/20 - 4x/20 = 7
20x/20 - 19x/20 = 7
x /20 = 7
x = 7*20
x = 140 cows.