A flagstaff 17.5 m high casts a shadow of length 40.25 m. The height of the building, which casts a shadow of length 28.75 m under similar conditions will be:
10 m
12.5 m
17.5 m
21.25 m
Explanation:
Let the height of the building $ x $ metres.
Less lengthy shadow, Less in the height (Direct Proportion)
$\therefore$ 40.25 : 28.75 :: 17.5 : $ x $ $\Leftrightarrow$ 40.25 x $ x $ = 28.75 x 17.5
| $ x $ =$ \dfrac{28.75 \times 17.5}{40.25} $ |
$\Rightarrow x $ = 12.5