Mathematical Reasoning
String A is 3/4 the length of string B. String C is 80% the length of string A. What is the ratio of the leng…
Question 1 · Multiple choice
Question
String A is 3/4 the length of string B. String C is 80% the length of string A. What is the ratio of the length of string A to string B to string C?
Options
- A.3 : 4 : 12
- B.15 : 20 : 12
- C.12 : 15 : 20
- D.20 : 15 : 12
- E.3 : 5 : 4
Correct answer
Explanation
Step 1: Choose a convenient length for string B
Let B = 20 units (divisible by 4 and 5 for clean calculations).
Step 2: Find A
A = 3/4 × B = 3/4 × 20 = 15 units
Step 3: Find C
C = 80% × A = 0.8 × 15 = 12 units
Step 4: Write the ratio
A : B : C = 15 : 20 : 12
Check if they can be simplified: GCD(15, 20, 12) = 1. Already in simplest form.
A: ███████████████ 15 units
B: ████████████████████ 20 units
C: ████████████ 12 units
Answer: A : B : C = 15 : 20 : 12