8 times 8 would be 64. :)
The first day of the month would be the first saturday.
The days she has recorded: 11 + 10 + 7 + 6 + 3 + 2 = 39
The mode distance (most often): 5 km
Median distance: 6.64 km ~= 6.5 km ~= 7 km by rounding upwards, so 3rd
Cumulative frequency: 11; 21; 28; 34; 37; 39
The perimeter is just adding all the sides together.
a.) 180 = 40 + 40 + x + x
180 = 80 + 2x Subtract 80 on both sides
100 = 2x Take 1/2 of 100 to get x
x= 50cm
b.) 1000 = 150 + 150 + x + x
1000 = 300 + 2x Subtract 300 on both sides
700 = 2x Take 1/2 of 700 to get x
x = 350