You take how many shirts she sold and then multiply it by the cost of one shirt.
Therefore, you do 39 shirts * $16.50, which is equal to $643.50 in revenue :)
8000 because u add an extra 0 if u multiple with a number with a zero or no
He arrives at work at 7:50. all you need to do is go back 40 and then you get 8. Then you go back ten more minutes and you get 7:50 am
The length of a side of the square would be 8.