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D is 4 years younger than B and C is 4 years older than A. A and B are twins. If the average age of all the four boys is 11 years, then the sum of the ages of the youngest and the oldest boy is
  • a)
    22 years
  • b)
    20 years
  • c)
    24 years
  • d)
    18 years
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
D is 4 years younger than B and C is 4 years older than A. A and B ar...
Let the age of A = B = y years
Age of D = y-4 years
Age of C = y+4 years
Then,
y-4+y+y+y+4 = 4 x11
y = 11
Sum of ages of the youngest and oldest boy = 7+15 = 22 years
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Most Upvoted Answer
D is 4 years younger than B and C is 4 years older than A. A and B ar...
To solve this problem, we need to use a system of equations. Let's assign variables to the ages of each boy:

Let A be the age of the youngest boy (twins with B)
Let B be the age of the second youngest boy (twins with A)
Let C be the age of the third youngest boy
Let D be the age of the oldest boy

From the given information, we can deduce the following equations:

Equation 1: D = B - 4 (D is 4 years younger than B)
Equation 2: C = A + 4 (C is 4 years older than A)
Equation 3: (A + B + C + D) / 4 = 11 (The average age of all four boys is 11 years)

Let's solve these equations step by step:

Step 1: Substitute Equation 1 and Equation 2 into Equation 3:

(A + B + A + 4 + B - 4) / 4 = 11

Simplify:

(2A + 2B) / 4 = 11

Divide both sides by 2:

(A + B) / 2 = 11

Multiply both sides by 2:

A + B = 22

Step 2: Substitute Equation 1 into Equation 2:

C = A + 4
B - 4 = A + 4

Simplify:

B = A + 8

Step 3: Substitute the value of B from Step 2 into the equation A + B = 22:

A + (A + 8) = 22

Combine like terms:

2A + 8 = 22

Subtract 8 from both sides:

2A = 14

Divide both sides by 2:

A = 7

Step 4: Substitute the value of A into the equation B = A + 8:

B = 7 + 8
B = 15

Step 5: Substitute the values of A and B into Equation 1 to find the value of D:

D = B - 4
D = 15 - 4
D = 11

Now we have the ages of all four boys:

A = 7
B = 15
C = 7 + 4 = 11
D = 15 - 4 = 11

Step 6: Find the sum of the ages of the youngest and the oldest boy:

Sum = A + D
Sum = 7 + 11
Sum = 18

Therefore, the sum of the ages of the youngest and the oldest boy is 18 years.
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D is 4 years younger than B and C is 4 years older than A. A and B are twins. If the average age of all the four boys is 11 years, then the sum of the ages of the youngest and the oldest boy isa)22 yearsb)20 yearsc)24 yearsd)18 yearsCorrect answer is option 'A'. Can you explain this answer?
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D is 4 years younger than B and C is 4 years older than A. A and B are twins. If the average age of all the four boys is 11 years, then the sum of the ages of the youngest and the oldest boy isa)22 yearsb)20 yearsc)24 yearsd)18 yearsCorrect answer is option 'A'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about D is 4 years younger than B and C is 4 years older than A. A and B are twins. If the average age of all the four boys is 11 years, then the sum of the ages of the youngest and the oldest boy isa)22 yearsb)20 yearsc)24 yearsd)18 yearsCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for D is 4 years younger than B and C is 4 years older than A. A and B are twins. If the average age of all the four boys is 11 years, then the sum of the ages of the youngest and the oldest boy isa)22 yearsb)20 yearsc)24 yearsd)18 yearsCorrect answer is option 'A'. Can you explain this answer?.
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