Question

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

Answer:

b)9.8

hope this answer useful to you mate

Answer 2

$\bf{\huge{\underline{\boxed{\sf{\green{Answer:}}}}}}$

$\bf{\underline{\sf{\red{Given:}}}}$

• Height of the pole = 14 m
• Height of the shadow = 10 m
• Length of the shadow casted by a tree = 7 m

$\bf{\underline{\sf{\red{To\:find:}}}}$

• Height of the tree

$\bf{\underline{\sf{\red{Solution:}}}}$

We know that, the greater the height of the pole will be, the larger the height of the shadow casted by the pole will be.

It implies that the ratio of the length of the pole and shadow are in direct variation. If one quantity of the ratio increases ultimately the other quantity too will increase.

Height of the pole = 14

Height of the shadow = 10 m

Length of the shadow casted by a tree = 7 m

Let the height of the tree be x m.

Since the ratio are in direct variation, they are equal to a constant. Let's represent it mathematically.

For pole :-

=> $\bf\large\sf\frac{14}{10}$ = k -----> 1

For tree :-

=> $\bf\large\sf\frac{x}{7}$ = k ------> 2

From equations 1 and 2,

=> $\bf\large\sf\frac{14}{10}$ = $\bf\large\sf\frac{x}{7}$

Cross multiplying,

=> 14 × 7 = x × 10

=> 98 = 10x

=> $\bf\large\sf\frac{98}{10}$ = x

=> 9.8 = x

•°• Height of the tree is 9.8 m