Answer: D represents the price of a sandwich and a smoothie
The number of situps form an AP with first term (a) = 17 and common difference (d) = 4
Tn = a + (n - 1)d
T12 = 17 + (12 - 1) x 4 = 17 + 11(4) = 17 + 44 = 61
Therefore, she will do 61 situps on day 12.
By Pythagoras AB^2 = 12^2 - 6^2 = 108
AB = sqrt 108 = 10.39 to nearest hundredth
The perpendicular from M to DC will be parallel and equal to AB so it = 10.39.
Also AB^2 = CB * DB
108 = 6 * DB
DB = 108/6 = 18
so DC = 18-6 = 12
MD^2 = (1/2*12)^2 + 108 = 144
so MD = 12
Nathaniel is correct. fractions are rational numbers