Question

Tick (✓) the correct answer:
A pole 14 m high casts a shadow of 10 m. At the same time, what will be the height of a tree, the length of whose shadow is 7 metres?
(a) 20 m
(b) 9.8 m
(c) 5 m
(d) none of these

Answer 1

(b) 9.8 m
Let x m be the height of the tree.

Height of object	14	$x$
Length of shadow	10	7

The more the length of the shadow, the more will be the height of the tree.
$$\begin{gathered} \mathrm{Now},\frac{14}{10}=\frac{x}{7} \\ \Rightarrow x=\frac{14\times 7}{10} \\ \Rightarrow x=9.8 \end{gathered}$$

Therefore, a 9.8 m tall tree will cast a shadow of length 7 m.