Hey there!
You can answer this question by adding up all of the reservations and finding the percentage of reservations made on Friday or Saturday out of that total. First, find the total, then, add up the reservations for Friday and Saturday.
15 + 5 + 10 + 25 + 40 + 30 + 35 = 160
40 + 30 = 70
Now, divide the reservation amount for Friday and Saturday by the total amount and multiply this decimal by 100 to get your percentage.
70 ÷ 160 = 0.4375
0.4375 × 100 = 43.75%
Hope this helped you out! :-)