Question

Question 114.
Mary bought 3$\frac{1}{2}$ m of lace. She used 1$\frac{3}{4}$ m of lace for her new dress. How much lace is left with her?

Answer 1

Given that

Mary bought lace of length = 3$\frac{1}{2}$ m
and lace used for new dress = 1$\frac{3}{4}$ m
In order to find the lace left with her, we will subtract 1$\frac{3}{4}$ m from 3$\frac{1}{2}$ m.

We can express a mixed fraction as an improper fraction as $\frac{(\text{Whole}\times \text{Denominator})\text{+ Numerator}}{\text{Denominator}}$.

$\therefore 3\frac{1}{2}=\frac{3\times 2+1}{2}=\frac{7}{2}$

$\therefore 1\frac{3}{4}=\frac{1\times 4+3}{4}=\frac{7}{4}$

The LCM of the denominator of the fractions $\frac{7}{2}$ and $\frac{7}{4}$ i.e. the LCM if 2 and 4 is 4.

$\therefore 3\frac{1}{2}-1\frac{3}{4}=\frac{7}{2}-\frac{7}{4}=\frac{7\times 2-7}{4}=\frac{14-7}{4}=\frac{7}{4}=1\frac{3}{4}$

So, 1$\frac{3}{4}$ m lace is left with her.