Set the number of chickens as x and number of cows as <span>y </span>so the farmer has total 28 animals so x+y=28 you know that since the animals are healthy chickens will have 2 legs and cows will have 4 legs the total number of legs are 64 so 2x+4y=64 since you want to find the number of cows so from the first equation <span>x+y=28 </span>we will get another equation<span>x=28-y </span>then plug into <span>2x+4y=64 2(28-y)+4y=64 56-2y+4y=64 56+2y=64 -56 -56 2y=8 y=4 </span>
The probability that the first horse wins is 2/7. The probability that the second horse wins is 3/10. Since the events that the first horse wins and the second horse wins are shared exclusive, the probability that either the first horse or the second horse will win is :
