Which question is being asked in this story problem?

martin has a rock collection and a book collection. he has a total of 60 rocks and books combined in his collection. he has 24 rocks in his collection.

how many books are in martin's collection?

a.
how many rocks does martin have in his collection?

b.
how many items does martin have in his rock collection and book collection combined?

c.
how many more books than rocks does martin have in his collection?

d.
what is the total number of books in martin's collection?

Statement reason 1. δabc is similar to δced. given 2. 3. definition of slope 4. slope of slope of definition of slope 5. slope of × slope of multiplying the slopes 6. slope of × slope of substitution property of equality 7. slope of × slope of simplifying the right side the table contains the proof of the relationship between the slopes of two perpendicular lines. what is the reason for statement 2? a. parallel line segments that meet a common perpendicular line are proportional in length. b. the lengths of vertical and horizontal sides in congruent triangles are in a common ratio. c. trigonometric identities determine the lengths of the legs in a right triangle. d. corresponding side lengths in similar triangles are proportional in length.