Surya is 25 years older than his son. In 5 years, he will be twice as old as his son. What will be Surya’s age after 3 years?
48
This problem involves figuring out the current ages of Surya and his son based on the given information and then calculating Surya's age in the future. We can solve this by setting up algebraic equations.
Let's define variables for their current ages:
Now, we translate the given information into equations:
Information 1: Surya is 25 years older than his son.
This can be written as an equation:
\(S = Y + 25 \quad (Equation\ 1)\)
Information 2: In 5 years, he will be twice as old as his son.
First, let's find their ages in 5 years:
Now we have two equations with two variables:
\(Equation\ 1:\ S = Y + 25\)
\(Equation\ 2:\ S = 2Y + 5\)
Since both equations are equal to \(S\), we can set them equal to each other to solve for \(Y\):
\(Y + 25 = 2Y + 5\)
Now, solve for \(Y\):
Subtract \(Y\) from both sides:
\(25 = 2Y - Y + 5\)
\(25 = Y + 5\)
Subtract 5 from both sides:
\(25 - 5 = Y\)
\(20 = Y\)
So, the son's current age (\(Y\)) is 20 years.
Now substitute the value of \(Y\) (20) back into Equation 1 to find Surya's current age (\(S\)):
\(S = Y + 25\)
\(S = 20 + 25\)
\(S = 45\)
So, Surya's current age (\(S\)) is 45 years.
The question asks for Surya's age after 3 years. His current age is 45 years.
Surya's age after 3 years = Current age + 3 years
Surya's age after 3 years = \(45 + 3\)
Surya's age after 3 years = \(48\)
Therefore, Surya will be 48 years old after 3 years.
Let's check if these ages satisfy the conditions:
The calculated ages satisfy both conditions.
| Concept | Explanation | How it applies here |
|---|---|---|
| Defining Variables | Represent unknown quantities (ages) with letters (e.g., \(S\), \(Y\)). | \(S\) for Surya's age, \(Y\) for son's age. |
| Forming Equations | Translate word statements about relationships between ages into algebraic equations. | \(S = Y + 25\), \(S + 5 = 2(Y + 5)\). |
| Solving Simultaneous Equations | Use substitution or elimination method to find the values of variables. | Substituted \(Y + 25\) for \(S\) into the second equation. |
| Future/Past Ages | Add or subtract the given number of years from the current age. | Ages in 5 years are \(S+5\) and \(Y+5\). |
Age problems are common types of word problems in algebra. They typically involve finding the current ages of people based on information about their relative ages at different points in time (past, present, or future). The key to solving these problems is careful translation of the word statements into algebraic equations.
Practicing different types of age problems helps in understanding how to set up the equations correctly.
Six years ago, the ratio of ages of A to B was 7 ∶ 5. After 4 years from now, the ratio of their ages will be 11 ∶ 9. What is A’s age at present?
7p - [3q - {8p - (4q - 10p)}] = ?
The difference between the ages of two sisters is 2 years when father’s age is 52. Father is elder by 2 years to mother. Elder sister’s age is half of mother’s age. Find the age of younger sister?
The sum of the digits of a 2 digit number is 9, When 27 is added to the number, the digits get interchanged. Find the number.
A. 45
B. 36
C. 18
D. 27If a + 2b = 55 and a – 2b = - 13, find the value of b.
A. 21
B. 14
C. 17
D. 19