Answer:
15 teaspoons = 150 grams
20 teaspoons = 200 grams
Explanation:
We know that there are 10 grams of Lithium in on teaspoon.
If we want to find the amount in 15 teaspoons, we multiply by 10.
15 x 10 = 150
We also do the same process for 20 teaspoons.
20 x 10 = 200
Hope this helps you!