2/3 of 18...." of " means multiply
2/3 * 18 = 36/3 = 12....she has memorized 12 words so far
I think it's B. 13/10 * 4
Explanation:
It's +0.3 more servings, so it would rule out C and D, which uses the digit 7(nothing to do with this problem.
13/10 instead of 3/10 because it's adding 0.3. More than 4L
16,24,32,40.48,56,64,72,80,88
It would take 2 pairs of complementary angles because complementary angles have 90 degrees and 180 degrees makes a straight line