English

A 5 m 60 cm high vertical pole casts a shadow 3 m 20 cm long. Find at the same time the height of a pole which casts a shadow 5 m long.

Advertisements
Advertisements

Question

A 5 m 60 cm high vertical pole casts a shadow 3 m 20 cm long. Find at the same time the height of a pole which casts a shadow 5 m long.

Sum
Advertisements

Solution

Given,

length of shadow of 5 m 60 cm high vertical pole = 3 m 20 cm

We know that 5 m 60 cm = 5 × 100 + 60

= 500 + 60

= 560 cm

3 m 20 cm = 3 × 100 + 20

= 300 + 20

= 320 cm

Length of shadow of second pillar = 5 m

= 5 × 100

= 500 cm

Let the length of the pillar = y

ratio of both

Then `560/320 = y/500`

on multiplying thunderbolts

`320 × y = (560×500)/30`

`y = (560×500)/320`

y = 875

Hence, length of shadow of the pillar = 875 cm

= 8 m 75 cm

shaalaa.com
  Is there an error in this question or solution?
Chapter 11: Direct and Inverse Proportions - EXERCISE 11.1 [Page 136]

APPEARS IN

NCERT Mathematics [English] Class 8
Chapter 11 Direct and Inverse Proportions
EXERCISE 11.1 | Q 9. (ii) | Page 136

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Fill in the blank in of the following so as to make the statement true:

 If u = 3 v, then u and v vary .... with each other.


68 boxes of a certain commodity require a shelf-length of 13.6 m. How many boxes of the same commodity would occupy a shelf length of 20.4 m?


A and B can do a piece of work in 18 days; B and C in 24 days and A and C in 36 days. In what time can they do it, all working together?


Working 8 hours a day, Ashu can copy a book in 18 days. How many hours a day should he work so as to finish the work in 12 days?

 

The scale of a map is given as 1:30000000. The two cities are 4 cm apart on the map. Find the actual distance between them.

A group of 21 students paid ₹ 840 as the entry fee for a magic show. How many students entered the magic show if the total amount paid was ₹ 1680?


By travelling at a speed of 48 kilometres per hour, a car can finish a certain journey in 10 hours. To cover the same distance in 8 hours, the speed of the car should be ______.


Both x and y vary directly with each other and when x is 10, y is 14, which of the following is not a possible pair of corresponding values of x and y?


Two quantities x and y are said to vary directly with each other if for some rational number k, xy = k.


Here is a key board of a harmonium:

  1. Find the ratio of white keys to black keys on the keyboard.
  2. What is the ratio of black keys to all keys on the given keyboard.
  3. This pattern of keys is repeated on larger keyboard. How many black keys would you expect to find on a keyboard with 14 such patterns.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×