Subject
Quantitative Aptitude
Topic
Areas & Volumes
Mr Ali decided to walk down the escalator of a tube station. He found that if he walks down 26 steps, he requires 30 seconds to reach the bottom. However, if he steps down 34 stairs he would only require 18 seconds to get to the bottom. If the time is measured from the moment the top step begins to descend to the time he steps off the last step at the bottom, find out the height of the stair way in steps?
Mr Ali decided to walk down the escalator of a tube station. He found that if he walks down 26 steps, he requires 30 seconds to reach the bottom. However, if he steps down 34 stairs he would only require 18 seconds to get to the bottom. If the time is measured from the moment the top step begins to descend to the time he steps off the last step at the bottom, find out the height of the stair way in steps?
ক)
23 stepsখ)
16 stepsগ)
46 stepsঘ)
26 steps//none of themExplanation
Let the staircase have n steps Now, Mr Shah covers n - 26 steps in 30 seconds and n - 34 steps in 18 seconds. Assuming that Mr Shah's speed in either case is same, we have (n - 26)/30 = (n - 34)/18 18n - 18*26 = 30n - 30*34 12n = 30*34 - 18*26 n = 552/12 n = 46 stepsRelated questions
The ratio between the length and the breadth of a rectangular park is 3 : If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 8 minutes, then the area of the park (in sq. m) is:How many bricks, each measuring 25 cm x 25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 5 cm?A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered.If the area of the field is 680 sq.ft, how many feet of fencing will be required?A cistern of capacity 8000 litres measures externally 3 m by 6 m by 1 m and its walls are 5 cm thick. The thickness of the bottom is:The curved surface area of a cylindrical pillar is 264 m2and its volume is 924 m3. Find the ratio of its diameter to its height.A man walking at the speed of 4 kmph crosses a square field diagonally in 3 meters.The area of the field isA metallic sheet is of rectangular shape with dimensions 48 m x 36 m. From each of its corners, a square is cut off so as to make an open box. If the length of the square is 8 m, the volume of the box (in m3) is: