The World of Numbers | Exercise 3.4

Question 3

Simplify the expression: (14)+(512)\left(-\frac{1}{4}\right) + \left(\frac{5}{12}\right).

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Solution

We need to add two fractions with different denominators.

Step 1 — Find common denominator

Let's find the Least Common Multiple (LCM). The denominators are 4 and 12. The LCM of 4 and 12 is 12.

We convert the first fraction to have denominator 12. 14=1×34×3-\frac{1}{4} = -\frac{1 \times 3}{4 \times 3}

312\boxed{-\frac{3}{12}}

Diagram 1

Step 2 — Add the fractions

Now we add the fractions with the same denominator. 312+512-\frac{3}{12} + \frac{5}{12} =3+512= \frac{-3 + 5}{12} =212= \frac{2}{12} =16= \frac{1}{6}

Answer

(i) The simplified expression is 16\frac{1}{6}.

More questions in Exercise 3.4

Q1

Represent the rational numbers 23\frac{2}{3}, 54-\frac{5}{4} and 1121\frac{1}{2} on a single number line.

Q2

Find three distinct rational numbers that lie strictly between 12-\frac{1}{2} and 14\frac{1}{4}.

Q3

Simplify the expression: (14)+(512)\left(-\frac{1}{4}\right) + \left(\frac{5}{12}\right).

Q4

A tailor has 153415\frac{3}{4} metres of fine silk. If making one kurta requires 2142\frac{1}{4} metres of silk, exactly how many kurtas can he make?

Q5

Find three rational numbers between 3.1415 and 3.1416.

Q6

Can you think of other way(s) to find a rational number between any two rational numbers?

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