It depends what is in the teaspoon--some things weigh more than others.
On average, a teaspoon of water, salt, sugar, and similar items weighs 5 grams.
A teaspoon of something lighter, such as powdered sugar, will weigh less.
There are 1000 mg in one gram, so your question of 15-30 mg is far less than a teaspoon (250 mg would be 1/4 teaspoon).
Two 15s' equals 30.
Seven of them.
12r - 15s - r + 3s = 11r -12s
15s=58.5 s=58.5/15 s =3.9
(change in velocity)/(change in time)=avg. acceleration (-30 m/s)/(15s)= -2 m/s2
Two 15s' equals 30.
30
16h 53m 15s, −30° 44′ 12″
678
Seven of them.
18.53
Exactly 8 of them
16h 53m 15s, −30° 44′ 12″
15s-15 = 0
2
The coordinates 15S, 75W represent a location in Peru, in or near Poroma on the Panamericana Sur.
12r - 15s - r + 3s = 11r -12s