NCERT Solutions Ganita Prakash (Part 1) Chapter 1 (Getting a Feel of Large Numbers)1.1 A Lakh Varieties! — In-text Questions
Book page 3 Updated on2026-09-05
Q1.
Look at the picture on the right. Somu is 1 metre tall. If each floor is about four times his height, what is the approximate height of the building?
Answer
The building in the picture has 10 floors, so its height is about 40 metres.
Somu's height = 1 m Height of one floor = 4 × 1 m = 4 m Number of floors in the picture = 10 Height of building = 10 × 4 m = 40 m
Why it happens: Somu is standing on the balcony of the topmost floor. Counting the balconies down the picture gives 10 of them, and each one is a storey four times his own height. Multiplying 4 m by 10 storeys gives 40 m.
Tip: Remember this 40 m building — the chapter uses it again and again as a “measuring stick” for the Statue of Unity, the Kunchikal waterfall, Mount Everest and aeroplanes.
Q2.
Which is taller — The Statue of Unity or this building? How much taller? ____________ m.
Answer
The Statue of Unity is taller, by 140 m.
Height of Statue of Unity = 180 m Height of Somu's building = 40 m Difference = 180 − 40 = 140 m
Why it happens: 180 ÷ 40 = 4.5, so the statue is about four and a half times Somu's building. The book puts it as “close to 4 times the height of Somu's building”.
Did you know? The Statue of Unity in Kevadia, Gujarat is the world's tallest statue — you would have to stack about 4½ ten-storey buildings to match Sardar Patel's head.
Q3.
How much taller is the Kunchikal waterfall than Somu's building? ____________ m.
Answer
The waterfall is 410 m taller than the building.
Height of Kunchikal waterfall = 450 m Height of Somu's building = 40 m Difference = 450 − 40 = 410 m
Why it happens: 450 ÷ 40 = 11.25, so the waterfall is more than eleven times as tall as the whole building. That is why a 450 m drop is hard to picture until you compare it with something you know.
Did you know? Kunchikal falls, on the Varahi river in Shivamogga district of Karnataka, is one of India's highest waterfalls.
Q4.
How many floors should Somu's building have to be as high as the waterfall? ____________ .
Answer
About 113 floors.
Height of waterfall = 450 m Height of one floor = 4 m Number of floors = 450 ÷ 4 = 112.5 = 113 floors (you cannot build half a floor, so round up)
Why it happens: 112 floors reach only 448 m, which is 2 m short of the waterfall. One more floor takes the building to 452 m, just past the top of the fall — so 113 is the smallest whole number of floors that will do.
Try This: The tallest building in India is about 280 m. How many of Somu's floors is that? 280 ÷ 4 = 70 floors.