Question

Length and width of a field are in the ratio 5 : 3. If the width of the field is 42 m, then its length is

• A. 100 m
• B. 80 m
• C. 50 m
• D. 70 m

Answer 1

The correct option is D 70 m

Given: Ratio of length to the width of the field = 5 :3
Width of the field is 42 m.

Now, we need to find the length of the field when its width is 42 m.

Let the length of the field be $l$ m.

$5:3$ and $l:42$ are equivalent ratios.

$\Rightarrow$ $5:3=l:42m$

$\Rightarrow$ $\frac{5}{3}=\frac{l}{42}$

$\Rightarrow$ $42\times 5=3l$

$\Rightarrow$ $l=\frac{42\times 5}{3}$

$\therefore$ $l=70m$

Hence, when the width of the field is 42 m, the length of the field will be 70 m.