Subject
Quantitative Aptitude
Topic
Areas & Volumes
If the length of a rectangle is increased by 20% and the width is decreased by 20%, the area is?
If the length of a rectangle is increased by 20% and the width is decreased by 20%, the area is?
ক)
decreased by 8%খ)
decreased by 4%গ)
increased by 8%ঘ)
increased by 4%Explanation
ধরি, আয়তক্ষেত্রের প্রাথমিক দৈর্ঘ্য = L প্রাথমিক প্রস্থ = W প্রাথমিক ক্ষেত্রফল = L × W পরিবর্তনের পর, নতুন দৈর্ঘ্য = L + 20% of L = L + 0.2L = 1.2L নতুন প্রস্থ = W - 20% of W = W - 0.2W = 0.8W নতুন ক্ষেত্রফল = 1.2L × 0.8W = 0.96LW প্রাথমিক ক্ষেত্রফল = LW = 1.00LW নতুন ক্ষেত্রফল = 0.96LW পরিবর্তন = 0.96LW - 1.00LW = -0.04LW শতকরা পরিবর্তন = (-0.04LW/LW) × 100% = -4%Related 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: