Antonio has a total of 55 marbles. he has 15 green marbles and 12 red marbles. the rest of the marbles are blue. how many blue marbles does he have? a student solves this problem by writing an equation. which strategy could check the student’s answer? a. check that the sum of the final answer, 12, and 15 is 55. b. check that the difference of 55 and the final answer is 12. c. check that the sum of the final answer, 27 and 15 is 55. d. check that the difference of 55 and the final answer is 15.

C.Check that the sum of the final answer, 27 and 15 is 55.

Step-by-step explanation:

Given: The total number of marbles Antonio has = 55

The number of green marbles = 15

The number of red marbles = 12

Since, the rest of the marbles are blue.

Then to find the number of red marbles we need to subtract the sum of green marbles and red marbles from the total marbles,

The number of blue marbles =

Now,  to check the student’s answer he should check the sum of the final answer (28), 12, and 15 is 55.

i.e.

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6