All Exams Test series for 1 year @ ₹349 only
Question

25 divided by 1/5 = ?

This question was previously asked in
RRB ALP 2018 CBT 2 Fitter Question Paper (21-Jan-2019) (Shift 3)
The correct answer is

125

Understanding Division by Fractions

The question asks us to calculate the value of 25 divided by 1/5. Dividing by a fraction is equivalent to multiplying by the reciprocal of that fraction.

What is a Reciprocal?

The reciprocal of a fraction is found by flipping the numerator and the denominator. For example, the reciprocal of $\frac{a}{b}$ is $\frac{b}{a}$. The reciprocal of a whole number can be found by considering it as a fraction with a denominator of 1. For instance, the number 5 can be written as $\frac{5}{1}$, and its reciprocal is $\frac{1}{5}$. Similarly, the number 1/5 is a fraction, and its reciprocal is found by swapping the numerator (1) and the denominator (5), which gives us 5/1, or simply 5.

Calculating 25 Divided by 1/5

We need to solve the expression:

$\text{25} \div \frac{1}{5}$

According to the rule of dividing by fractions, we change the division operation ($\div$) to multiplication ($\times$) and use the reciprocal of the divisor (1/5). The reciprocal of 1/5 is 5.

So, the expression becomes:

$\text{25} \times 5$

Now, we simply multiply 25 by 5:

$25 \times 5 = 125$

Therefore, 25 divided by 1/5 is equal to 125.

Summary of the Calculation

  • Identify the numbers involved: 25 and 1/5.
  • Identify the operation: Division ($\div$).
  • Recall the rule for dividing by a fraction: Multiply by the reciprocal of the divisor.
  • Find the reciprocal of the divisor (1/5): It is 5.
  • Rewrite the problem as multiplication: $25 \times 5$.
  • Perform the multiplication: $25 \times 5 = 125$.
Original Problem Operation Change Divisor Reciprocal Equivalent Multiplication Result
$25 \div \frac{1}{5}$ Division to Multiplication Reciprocal of $\frac{1}{5}$ is 5 $25 \times 5$ 125

Revision Table: Dividing by Fractions

Concept Explanation Example
Dividing by a fraction Equivalent to multiplying by the reciprocal of the fraction. $a \div \frac{b}{c} = a \times \frac{c}{b}$
Reciprocal of a fraction Flip the numerator and denominator ($\frac{b}{c} \to \frac{c}{b}$). Reciprocal of $\frac{2}{3}$ is $\frac{3}{2}$.
Reciprocal of a whole number Write the number as $\frac{\text{number}}{1}$ and flip ($\frac{n}{1} \to \frac{1}{n}$). Reciprocal of 7 is $\frac{1}{7}$.

Additional Information: Inverse Operations

Division and multiplication are inverse operations. This means that one operation can 'undo' the other. The rule for dividing by a fraction using its reciprocal stems from this relationship. Multiplying by the reciprocal of a number is the same as dividing by that number. For example, multiplying by $\frac{1}{5}$ is the same as dividing by 5. Conversely, dividing by $\frac{1}{5}$ is the same as multiplying by 5 (the reciprocal).

Understanding reciprocals and inverse operations is fundamental for solving problems involving fractions and division.

Was this answer helpful?

Similar Questions

  1. Which of the fractions given below, when added to 5/8, give 1?

  2. A television show lasted for \(4\frac{2}{3}\) hours. If 1/5th of the total time was spent on advertisements, what was the actual duration of the television show?

  3. By what number should \(10\frac{2}{3}\) be divided to obtain 20?

  4. 23 × 31 = 713. How much is 0.0713 ÷ 3.1?

  5. A fraction, when taken away from \(\frac{1}{3}\)  gives  \(\frac{1}{12}\)  The fraction is:

  6. Tapan, Ravi and Trisha shared a cake. Tapan had 1/3 of it, Trisha had 1/2 of it and Ravi had the rest. What was Ravi’s share of the cake?

  7. Tapan, Ravi, and Trisha shared a cake. Tapan had 1/4 of it, Trisha had 2/3 of it and Ravi had the rest. What was Ravi’s share of the cake?

  8. The sum of two fraction is 19/20, one of them is 3/4. What is the other fraction?

  9. The sum of 4/7 and 7/4 is:

  10. 182/130 when written in the simplest form is:


Important Questions from Fractions

  1. 5 \(\frac{3}{4}\) + x + 2  \(\frac{1}{2}\) = 10  \(\frac{1}{8}\) Find the value of x.

  2. Simplify the expression 441 ÷  \(\left[270 \div \frac{3}{7}+\left(17\div \frac{1}{3}\right)-\left(8\frac{1}{2}-\frac{5}{2}\right)\right]\)

  3. Number 0.232323 can be written in rational form as:

  4. Solve: \(\frac{1}{2}\)  [{-2(2 + 3)*20}/2]

  5. Match the following.

    Column I

    Column II

    a.

    Equivalent fraction of \(\frac{7}{12}\)  is  

    i.

    Proper fraction

    b.

    Equivalent fraction of  \(\frac{9}{15}\)  is

    ii.

    Improper fraction

    c.

    \(\frac{7}{11}\)  is

    iii.

    \(\frac{21}{36}\)

    d.

    \(\frac{19}{5}\)  is

    iv.

    \(\frac{3}{5}\)

Need Expert Advice?
Upcoming Exams
RRB Technician
October 06, 2026
RRB JE
October 27, 2026
RRB ALP
November 03, 2026
Test Series
RRB ALP img
Railways
RRB ALP 2026 Mock Test series
1035 Tests 1 Tests Free
1080 Attempts
4.3(238)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App