A is 44 years old and B is 19 years old. After how many years will A be twice as old as B?
Solution
44 + x = 2(19 + x) ⇒ x = 44 − 38 = 6.
20 questions in the pattern of MAH MBA CET, NMAT and SNAP. Each question is marked with the exams it suits. Answer it, then open the step-by-step solution.
A is 44 years old and B is 19 years old. After how many years will A be twice as old as B?
44 + x = 2(19 + x) ⇒ x = 44 − 38 = 6.
A's father was 27 years old when A was born, and A's mother was 23 years old when A's brother, who is 6 years younger than A, was born. What is the difference between the parents' ages?
When A was born, the mother was 23 − 6 = 17 years old.
Difference = 27 − 17 = 10 years.
The ratio of A's and B's ages is 3 : 5. 8 years from now, the sum of their ages will be 64. What is B's present age?
Present sum = 64 − 16 = 48.
B = 5/8 × 48 = 30.
9 years ago, the ages of A and B were in the ratio 2 : 5. A is now 23 years old. How old is B now?
9 years ago A was 14 = 2k, so k = 7.
B then = 35; now 44.
The present ages of A and B are in the ratio 5 : 7. After 12 years the ratio will be 4 : 5. What is A's present age?
(5k + 12) : (7k + 12) = 4 : 5.
5(5k + 12) = 4(7k + 12) gives k = 4; A = 20.
The average age of a mother and her 5 children is 20 years. The average age of the children is 12 years. What is the mother's age?
Total = 6 × 20 = 120; children total 5 × 12 = 60.
Mother = 60 years.
The average age of a mother and her 4 children is 21 years. The average age of the children is 16 years. What is the mother's age?
Total = 5 × 21 = 105; children total 4 × 16 = 64.
Mother = 41 years.
The ages of two sisters are in the ratio 4 : 7 and differ by 27 years. What is the age of the elder sister?
Difference = 3 parts = 27, so one part = 9.
Elder = 7 × 9 = 63.
B is 4 years older than A, and C is 3 years older than B. The sum of their ages is 101. How old is C?
A = x, B = x + 4, C = x + 7. Sum = 3x + 11 = 101.
x = 30, so C = 37.
10 years ago, the ages of A and B were in the ratio 7 : 3. A is now 66 years old. How old is B now?
10 years ago A was 56 = 7k, so k = 8.
B then = 24; now 34.
A's father was 28 years old when A was born, and A's mother was 25 years old when A's brother, who is 2 years younger than A, was born. What is the difference between the parents' ages?
When A was born, the mother was 25 − 2 = 23 years old.
Difference = 28 − 23 = 5 years.
The ages of two children differ by 4 years, and the product of their ages is 60. What is the age of the elder child?
x(x + 4) = 60.
x = 6 works (6 × 10 = 60), so the elder is 10.
B is 8 years older than A, and C is 3 years older than B. The sum of their ages is 58. How old is C?
A = x, B = x + 8, C = x + 11. Sum = 3x + 19 = 58.
x = 13, so C = 24.
The present ages of A and B are in the ratio 7 : 2. After 8 years the ratio will be 8 : 3. What is A's present age?
(7k + 8) : (2k + 8) = 8 : 3.
3(7k + 8) = 8(2k + 8) gives k = 8; A = 56.
A father is 5 times as old as his son. After 15 years he will be 3 times as old as his son. What is the son's present age?
Let the son be s: 5s + 15 = 3(s + 15).
Solving gives s = 15.
The ages of two children differ by 6 years, and the product of their ages is 160. What is the age of the elder child?
x(x + 6) = 160.
x = 10 works (10 × 16 = 160), so the elder is 16.
The ages of two sisters are in the ratio 4 : 5 and differ by 8 years. What is the age of the elder sister?
Difference = 1 part = 8, so one part = 8.
Elder = 5 × 8 = 40.
A is 46 years old and B is 17 years old. After how many years will A be twice as old as B?
46 + x = 2(17 + x) ⇒ x = 46 − 34 = 12.
The sum of the ages of a father and son is 54 years. After 3 years the father will be 5 times as old as the son. What is the father's present age?
Son = s, father = 54 − s. (54 − s + 3) = 5(s + 3).
Solving gives s = 7, so the father is 47.
The ratio of A's and B's ages is 2 : 7. 5 years from now, the sum of their ages will be 46. What is B's present age?
Present sum = 46 − 10 = 36.
B = 7/9 × 36 = 28.
These are original practice questions written by Target Campus in the pattern and difficulty of MAH MBA CET, NMAT, SNAP and other MBA entrance tests. They are not previous-year papers.
Preparing for MAH CET, SNAP or NMAT? Courses, live classes and mocks by Dr. Kiran Derle at Target Campus.
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