问题1.父亲的年龄是儿子的三倍。十二年后，他的年龄将是儿子的两倍，然后是儿子的两倍。找到他们现在的年龄。
解决方案：
Given, father’s age is 3 times as his son’s age.
Let the present age of father be ‘a’ and the present age of his son is ‘b’
So, by the given condition, a = 3b ……(1)
Also given, after twelve years, Father’s age is twice as his son’s age.
Therefore, (a + 12) = 2(b + 12)
⇒ a + 12 = 2b + 24
⇒ a = 2b + 12 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 3b = 2b + 12
⇒ b = 12
On putting b = 12 in eq(1), we get
a = 2(12) + 12 = 36
Hence, the present age of Father is 36 years and the present age of son is 12 years.
问题2。十年后，A的年龄将是B的两倍，而五年前，A的年龄将是B的三倍。A和B的年龄分别是多少?
解决方案：
Let, the present age of A and B are x, y respectively.
Given, Ten years later, A will be twice as old as B.
⇒ x + 10 = 2 (y + 10)
⇒ x = 2y + 10 ……(1)
Also given, Five years ago, A was thrice as old as B.
⇒ x – 5 = 3 (y – 5)
⇒ x = 3y – 10 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 2y + 10 = 3y – 10
⇒ y= 20.
On putting y = 20 in eq(1), we get
x = 2(20) + 10 = 50
Hence, the present ages of A is 50 years and B is 20 years.
问题3. A比B大2年。 A的父亲F的年龄是A的两倍，B的年龄是其姐姐S的两倍。如果父亲和妹妹的年龄相差40岁。然后找到A的年龄。
解决方案：
Let the present ages of A, B, A’s father F and A’s sister S are ‘a’, ‘b’, ‘c’, ‘d’ respectively.
Given, A is 2 years older than B.
⇒ a = b + 2 ……(1)
Also, A’s father F is twice as old as A and B is twice as old as his sister,
⇒ c = 2a and b = 2d ……(2)
Also given, the age of Father and sister differ by 40 years.
⇒ c – d = 40 ……(3)
On substituting d = b/2 and c = 2a from eq(2) and b = (a – 2) from eq(1) in eq(3), we get,
⇒ 2a – b/2 = 40
⇒ 2a – (a – 2)/2 = 40
⇒ 
⇒ 3a + 2 = 80
⇒ a = 26
Hence, the age of A is 26 years.
问题4：因此，一个男人的年龄将是儿子的六倍，而六年前的年龄是儿子的三倍。找到他们现在的年龄。
解决方案：
Let the present age of man and his son be x, y respectively.
Given, six years hence man’s age will be thrice as his son’s age.
⇒ x + 6 = 3 (y + 6)
⇒ x = 3y + 12 ……(1)
Also, three years ago, he was nine times as old as his son.
⇒ x – 3 = 9 (y – 3)
⇒ x = 9y – 24 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 3y + 12 = 9y – 24
⇒ y = 6
On putting y = 6 in eq(1), we get
x = 3(6) + 12 = 30
Hence, the present age of Man is 30 years and his son is 6 years.
问题5。十年前，父亲的年龄是儿子的十二倍，因此十年，父亲的年龄将是儿子的两倍。找到他们现在的年龄。
解决方案：
Let the present age of father and his son are ‘a’ and ‘b’ respectively.
Given, Ten years ago, father’s age is twelve times as his son’s age.
⇒ a – 10 = 12(b – 10)
⇒ a = 12b – 110 ……(1)
Also, ten years hence, his age will be twice as his son’s age.
⇒ a + 10 = 2 (b + 10)
⇒ a = 2b + 10 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 12b – 110 = 2b + 10
⇒ b = 12
On putting, b = 12 in eq(1), we get
a = 2(12) + 10 = 34
Hence, the present ages of Father is 34 years and his son is 12 years.
问题6.父亲的当前年龄是儿子年龄的三倍多。因此，父亲的年龄三年将比儿子的年龄大十倍。确定他们的年龄。
解决方案：
Let the age of father and his son are ‘a’ and ‘b’ respectively.
Given, Present age of father is three years more than three times his son’s age.
⇒ a = 3b + 3 ……(1)
Also, Three years hence, father’s age will be 10 years more than twice his son’s age.
⇒ a + 3 = 2 (b + 3) + 10
⇒ a = 2b + 13 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 3b + 3 = 2b + 13
⇒ b = 10
On putting, b = 10 in eq(1), we get
a = 3(10) + 3 = 33
Hence, present age of Father is 33 years and his son’s age is 10 years.
问题7：父亲的年龄是儿子的三倍。在12年的时间里，他的年龄将是儿子的两倍。找到父亲和儿子的现代年龄。
解决方案：
Let the present ages of father and his son be ‘a’ and ‘b’ respectively.
Given, Father is three times as old as his son.
⇒ a = 3b ……(1)
Also, After 12 years, he will be twice as old as his son.
⇒ a + 12 = 2 (b + 12)
⇒ a = 2b + 12 ……(2)
On substituting, eq(1) in eq(2), we get,
⇒ 3b = 2b + 12
⇒ b = 12
On putting, b = 12 in eq(1), we get
a = 3(12) = 36
Hence, the present age of Father is 36 years and his son is 12 years.
问题8：父亲的年龄是两个孩子的年龄之和的三倍。 5年后，他的年龄将是两个孩子的年龄总和的两倍。找到父亲的年龄。
解决方案：
Let the present ages of father and sum of ages of his two children are ‘a’, ‘b’ respectively.
Given, Father’s age is three times the sum of ages of his children.
⇒ a = 3b ……(1)
Also, after 5 years, his age will be twice the sum of ages of his two children.
⇒ a + 5 = 2(b + 10)
⇒ a = 2b + 15 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 3b = 2b + 15
⇒ b = 15
On putting b = 15 in eq(1), we get
a = 3(15) = 45
Hence, the age of Father is 45 years.
问题9.两年前，父亲的年龄是儿子的五倍。两年后，他的年龄将是儿子年龄的三倍，即八岁。找到父亲和儿子的现代年龄。
解决方案：
Let the present ages of Father and his son are ‘a’ and ‘b’ respectively.
Given, two years before, father’s age is five time the age of his son.
⇒ a – 2 = 5 (b – 2)
⇒ a = 5b – 8 ……(1)
Also, after two years, his age will be 8 more than thrice the age of the son.
⇒ a + 2 = 3 (b + 2) + 8
⇒ a = 3b + 12 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 5b – 8 = 3b + 12
⇒ b = 10
On putting, b = 10 in eq(1), we get
a = 3(10) + 12 = 42
Hence, the present age of Father is 42 years and his son is 10 years.
问题10。五年前，努里(Nuri)的年龄是索努(Sonu)的三倍。十年后，努里(Nuri)的年龄将是索努(Sonu)的两倍。 Nurl和Sonu多大了?
解决方案：
Let the present ages of Nuri and Sonu are ‘a’ and ‘b’ respectively.
Given, five years ago, Nuri was thrice as old as Sonu.
⇒ a – 5 = 3 (b – 5)
⇒ a = 3b -10 ……(1)
Also, after ten years Nuri will be twice as old as Sonu.
⇒ a + 10 = 2 (b + 10)
⇒ a = 2b + 10 ……(2)
On substituting eq(1) in eq(2), we get,
⇒ 3b – 10 = 2b + 10
⇒ b = 20.
On putting b = 20 in eq(1), we get
a = 2(20) + 10 = 50
Hence, the present age of Nuri is 50 years and Sonu is 20 years.
问题11：两个朋友阿尼和比茹的年龄相差3年。阿妮(Ani)的父亲达兰(Dharam)的年龄是阿妮(Ani)的两倍，比茹(Biju)的年龄是他姐姐凯西(Cathy)的两倍。凯茜(Cathy)和达兰(Dharam)的年龄相差30岁。找出Ani和Biju的年龄。
解决方案：
Let the present ages of Ani, Biju, Cathy, and Dharam are ‘a’, ‘b’, ‘c’ and ‘d’ respectively.
Given, Ani and biju differ by 3 years.
⇒ a – b = 3 ……(1)
Also, Dharam is twice as old as Ani and Biju is twice as old as his Cathy.
⇒ d = 2a and b = 2c ……(2)
Also given, the ages of Cathy and Dharam differ by 30 years.
⇒ d – c = 30 ……(3)
On substituting, d = 2a in eq(3) and a= b + 3 in eq(1), we get,
⇒ 2a – c = 3.
⇒ 2(b + 3) – b/2 = 30
⇒ 3b/2 = 24
⇒ b = 16
On substituting b in eq(1), we get
a = 3 + 16 = 19
Hence, the present age of Ani is 19 years and Biju is 16 years.
问题12.两年前，萨利姆(Salim)的年纪是他女儿的三倍，六年后，他的年龄将比她的年龄大四倍。他们现在几岁了?
解决方案：
Let the present ages of Salim and his daughter are ‘a’ and ‘b’ respectively.
So, two years ago, Salim was thrice as old as his daughter
(a – 2) = 3(b – 2)
a – 2 = 3b – 6
a – 3b + 4 = 0
a = 3b – 4 ……(1)
Also, after six years, Salim will be four years older than twice his daughter’s age
(a + 6) = 2(b + 6) + 4
a + 6 = 2b + 12 + 4
a + 6 = 2b + 16
a – 2b – 10 = 0
a = 2b + 10 ……(2)
On substituting eq(1) in eq(2), we get,
3b – 4 = 2b + 10
b = 14
On putting b = 14 in eq(1), we get
a = 3(14) – 4
a = 38
Hence, the present age of Salim is 38 years and his daughter is 14 years.
问题13：父亲的年龄是两个孩子的年龄之和的两倍。 20岁之后，他的年龄将等于其子女年龄的总和。找到父亲的年龄。
解决方案：
Let the ages of father and his two children are ‘a’ and ‘b’ respectively.
So, a = 2b …..(1)
So, after 20 years, his age will be equal to the sum of the ages of his children
a + 20 = b + 40
a = b + 20 …..(1)
On substituting eq(1) in eq(2), we get,
2b = b + 20
b = 20
On putting b = 20 in eq(1), we get
a = 2(20)
a = 40
Hence, the age of father is 40 years.