There are 339 brown cows and 170 black cows on the farm how many more brown cows are there then black

Me. i can't figure out this question. give an explanation too. .

80 points suppose marcy made 45 posts online. if 23 of them contained an image, what percent of her posts had images? round your answer to the nearest whole percent. 54 percent 51 percent 49 percent 48 percent

Alex took his brother to a birthday party. the party was scheduled to last for 1 and 3/4 hours but they stayed for 4/5 of an hour more. how long did she stay at the party?