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09 Feb 2026, 20:00
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C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
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Question Stats:
87% (01:06) correct
13%
(00:51)
wrong
based on 76
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The bill of a ride in a cab is $x for the first mile and $y for every additional mile. What will be the bill for a 10-mile journey?
(1) The bill for a 5-mile journey is $20.
(2) The bill for a 3-mile journey is $16.
(1) The bill for a 5-mile journey is $20.
(2) The bill for a 3-mile journey is $16.
10 Feb 2026, 00:30
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ExpertsGlobal5
The ride bill calculation is based on :
First mile = $x
Subsequent mile after the first mile = $y per mile.
So , for 10 mile journey = x +9y = ?
Statement 1:
The bill for a 5-mile journey is $20.
x + 4y = 20
X and y can hold many values. Thus, Insufficient.
Statement 2:
The bill for a 3-mile journey is $16.
x +2y = 16
X and y can hold many values. Thus, Insufficient.
Combining both values, we get
2y = 4
y=2
x=12.
so, we can calculate x+9y = 12+9*2 = 30
Thus, Sufficient
Option C
10 Feb 2026, 02:53
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Understanding the Problem:
The cab charges $x for the first mile and $y for each additional mile.
Our target: Find the bill for a 10-mile journey = x + 9y
(First mile costs x, remaining 9 miles cost y each)
This is a "Value" type DS question - we need a unique numerical answer. Since we have two unknowns (x and y), we need two independent equations to solve for them.
---
Statement 1: The bill for a 5-mile journey is $20.
This gives us: x + 4y = 20
One equation, two unknowns - we cannot find unique values.
Test cases:
Case 1: x = 4, y = 4 → Check: 4 + 4(4) = 20 ✓ → 10-mile bill = 4 + 9(4) = $40
Case 2: x = 8, y = 3 → Check: 8 + 4(3) = 20 ✓ → 10-mile bill = 8 + 9(3) = $35
Different answers → Not Sufficient
---
Statement 2: The bill for a 3-mile journey is $16.
This gives us: x + 2y = 16
One equation, two unknowns - same problem.
Test cases:
Case 1: x = 4, y = 6 → Check: 4 + 2(6) = 16 ✓ → 10-mile bill = 4 + 9(6) = $58
Case 2: x = 8, y = 4 → Check: 8 + 2(4) = 16 ✓ → 10-mile bill = 8 + 9(4) = $44
Different answers → Not Sufficient
---
Combined:
Now we have two equations:
• x + 4y = 20
• x + 2y = 16
Subtract the second from the first:
2y = 4 → y = 2
Substitute back:
x + 4(2) = 20 → x = 12
10-mile bill = 12 + 9(2) = 12 + 18 = $30
We get a unique answer → Sufficient
---
Key Insight: With two unknowns, you need two independent equations. Each statement alone gives only one equation - not enough. Together, they form a solvable system.
Answer: C
The cab charges $x for the first mile and $y for each additional mile.
Our target: Find the bill for a 10-mile journey = x + 9y
(First mile costs x, remaining 9 miles cost y each)
This is a "Value" type DS question - we need a unique numerical answer. Since we have two unknowns (x and y), we need two independent equations to solve for them.
---
Statement 1: The bill for a 5-mile journey is $20.
This gives us: x + 4y = 20
One equation, two unknowns - we cannot find unique values.
Test cases:
Case 1: x = 4, y = 4 → Check: 4 + 4(4) = 20 ✓ → 10-mile bill = 4 + 9(4) = $40
Case 2: x = 8, y = 3 → Check: 8 + 4(3) = 20 ✓ → 10-mile bill = 8 + 9(3) = $35
Different answers → Not Sufficient
---
Statement 2: The bill for a 3-mile journey is $16.
This gives us: x + 2y = 16
One equation, two unknowns - same problem.
Test cases:
Case 1: x = 4, y = 6 → Check: 4 + 2(6) = 16 ✓ → 10-mile bill = 4 + 9(6) = $58
Case 2: x = 8, y = 4 → Check: 8 + 2(4) = 16 ✓ → 10-mile bill = 8 + 9(4) = $44
Different answers → Not Sufficient
---
Combined:
Now we have two equations:
• x + 4y = 20
• x + 2y = 16
Subtract the second from the first:
2y = 4 → y = 2
Substitute back:
x + 4(2) = 20 → x = 12
10-mile bill = 12 + 9(2) = 12 + 18 = $30
We get a unique answer → Sufficient
---
Key Insight: With two unknowns, you need two independent equations. Each statement alone gives only one equation - not enough. Together, they form a solvable system.
Answer: C
