NCERT Solutions for Class 7th Maths Chapter 5 …9…8…7…6…5…4…3…2…1…Take Off! — In-text Questions
Book page 116 – 11810 Updated on2026-09-19
Q1.
Look at the graph below showing the number of worldwide rocket launches by different organisations. Share your observations (you may take the teacher's help to identify the countries these organisations belong to).
Worldwide rocket launches by organisation for 2021, 2022 and 2023 — page 116.
Answer
The graph shows rocket launches for 2021, 2022 and 2023, with the bars drawn horizontally — so the length of a bar, not its height, gives the number.
Organisation
Country
2021
2022
2023
SpaceX
USA
≈ 31
≈ 61
≈ 96
CASC
China
≈ 48
≈ 35
≈ 45
Roscosmos
Russia
≈ 16
≈ 21
≈ 18
Arianespace
France
≈ 15
≈ 6
≈ 3
Rocket Lab
USA
≈ 6
≈ 6
≈ 9
United Launch Alliance
USA
≈ 5
≈ 8
≈ 3
ISRO
India
≈ 2
≈ 5
≈ 7
Galactic Energy
China
≈ 1
≈ 2
≈ 7
Expace
China
≈ 4
≈ 4
≈ 6
Other
many
≈ 18
≈ 17
≈ 26
SpaceX (USA) is far ahead of everyone, and it is growing fastest — its 2023 bar is longer than the whole of the CASC cluster put together.
The organisations are already arranged from longest to shortest, so the ranking can be read straight off.
China has three entries — CASC, Galactic Energy and Expace — and the USA has three as well: SpaceX, Rocket Lab and United Launch Alliance.
ISRO (India) is the only Indian entry and its launches rose every year, from about 2 to about 7.
The Other bars are not small: about 26 launches in 2023, more than any single organisation except SpaceX and CASC.
Careful: every number above is read off a bar, so it is an estimate, not an exact count. The graph itself prints no numbers. Say "about 31" and not "exactly 31".
Q2.
Step 1: Identify what is given. Notice how the graph is organised, what scale is used, and what patterns the data shows.
Worldwide rocket launches by organisation for 2021, 2022 and 2023 — page 116.
Answer
How it is organised. Each organisation gets three adjacent bars — one for 2021, one for 2022 and one for 2023 — shaded from dark to light. The organisations run down the left side, each with its country's flag beside it.
The scale.1 unit length = 20 rockets. The marks along the bottom read 0, 20, 40, 60, 80, 100.
The 'Other' category. It clubs together many smaller organisations from around the world, so that the graph does not become impossibly long.
Patterns worth noticing.
Increasing year on year: SpaceX — its 2022 bar is almost double its 2021 bar.
Decreasing year on year: Arianespace — its 2023 bar is about half its 2022 bar.
Increase and then decrease: United Launch Alliance — up from 2021 to 2022, then down sharply in 2023.
SpaceX's 2022 bar lands between the 60 and 80 marks, close to 60. Perhaps 61.
Why the order does not matter here: in the onion-price graph the months had to stay in order — January to December — because the whole point was the change over time. Here the organisations could be listed in any order and the meaning would not change. They have simply been sorted by size to make reading easier.
The boy in the book has a fair complaint: with gridlines only every 20 rockets, small bars like ISRO's and Galactic Energy's are hard to read. Lines at 5, 10 and 15 would make the short bars far easier to estimate.
Q3.
Step 2: Infer from what is given. Analyse and interpret each of your observations.
Page 116 — the graph of worldwide rocket launches by different organisations in 2021, 2022 and 2023.
Answer
Each observation from Step 1 now becomes a statement about the world.
The USA, China and Russia are the leading rocket-launching countries in these three years. The three USA organisations together and the three Chinese ones together account for most of the bars.
SpaceX launched about twice as many rockets in 2022 as in 2021 (about 61 against about 31), and about 35 more in 2023 than in 2022 (about 96 against about 61).
Arianespace's launches fell every year — about 15, then 6, then 3.
United Launch Alliance launched more in 2022 than in 2021, but fewer in 2023 than in either year.
Other organisations launched about 25 rockets in 2023, and the 'Other' total also grew, so small players are becoming more active.
ISRO's launches rose steadily, from about 2 to about 5 to about 7.
Why the two steps are kept separate: Step 1 is only about what your eyes can see — bar lengths, order, scale. Step 2 is where you say what it means. Mixing them is how people end up "seeing" things the graph never showed.
Q4.
Identify which of the following statements can be justified using this data. (a) All organisations launched more rockets than the previous years. (b) Only an organisation from the USA launched more than 50 rockets in a single year. (c) The total number of rockets launched by France in all 3 years is less than 40. (d) The average number of rockets launched by CASC in these 3 years is around 40. (e) ISRO launched more rockets than Galactic Energy in these 3 years. (f) Russia launched more than 60 rockets in these 3 years.
Answer
Statement
Justified?
The evidence in the graph
(a) All organisations increased every year
No
Arianespace fell every year; CASC fell in 2022; United Launch Alliance and Roscosmos fell in 2023. One counter-example is enough to break a claim that says all.
(b) Only a USA organisation crossed 50 in one year
Yes
SpaceX (USA) passed 50 twice — about 61 in 2022 and about 96 in 2023. The next longest bar anywhere is CASC's 2021 bar at about 48, which does not reach the halfway point between the 40 and 60 marks.
(c) France's total over 3 years is less than 40
Yes
France's only entry is Arianespace: about 15 + 6 + 3 = 24, comfortably under 40.
(d) CASC averages around 40
Yes
About 48 + 35 + 45 = 128, and 128 ÷ 3 ≈ 42.7 — which is "around 40".
(e) ISRO launched more than Galactic Energy
Yes
ISRO ≈ 2 + 5 + 7 = 14; Galactic Energy ≈ 1 + 2 + 7 = 10. Their 2023 bars are nearly equal, but ISRO's 2021 and 2022 bars are clearly longer.
(f) Russia launched more than 60 in 3 years
No
Russia's only entry is Roscosmos: about 16 + 21 + 18 = 55, which is below 60.
Why (f) needs care: 55 and 60 are close, and these are estimates read off bars with gridlines 20 apart. Even so, all three Roscosmos bars end well short of the 20-mark region needed to reach a total of 60, so the graph does not support the statement. Note also that if any Russian launches are hidden inside the 'Other' bars, the graph simply cannot tell us — another reason the claim is not justified.
Tip: statements (a) and (f) fail for different reasons. (a) is disproved by the graph — we can point at Arianespace. (f) is merely unsupported — the graph gives about 55, and it cannot rule out extra Russian launches sitting in 'Other'. "False" and "not shown" are not the same verdict.
Q5.
List the organisations that have consistently launched more rockets every year.
Answer
Reading the three bars of each cluster from dark to light, the ones that get longer every single time are:
SpaceX — about 31 → 61 → 96
ISRO — about 2 → 5 → 7
Galactic Energy — about 1 → 2 → 7
Organisation
Pattern across 2021 → 2022 → 2023
Consistent rise?
SpaceX
up, up
Yes
ISRO
up, up
Yes
Galactic Energy
up, up
Yes
Expace
level, then up
No — 2021 and 2022 look equal
Rocket Lab
about level, then up
No — the 2021 and 2022 bars are too close to call
Other
slightly down, then up
No
CASC, Roscosmos, ULA
up then down, or down then up
No
Arianespace
down, down
No — it fell every year
Why "consistently" is a strong word: it means every step must be an increase, not just the first and the last. Rocket Lab ended higher in 2023 than in 2021, but its middle bar does not clearly rise, so it does not qualify.
Where the graph runs out: Rocket Lab's and Expace's 2021 and 2022 bars are almost exactly the same length. At this scale the graph honestly cannot separate them, and the right answer is to say so rather than to guess.
Q6.
Estimate the total number of rockets launched worldwide in 2023. (a) less than 200 (b) 200 to 400 (c) 400 to 600 (d) more than 600
Answer
(b) 200 to 400. Adding the ten lightest bars gives roughly 220.
SpaceX ≈ 96
CASC ≈ 45
Roscosmos ≈ 18
Arianespace ≈ 3
Rocket Lab ≈ 9
United Launch Alliance ≈ 3
ISRO ≈ 7
Galactic Energy ≈ 7
Expace ≈ 6
Other ≈ 26 Total ≈ 220
Why this is the safe answer: even a generous reading of every bar cannot push the total past 250, and even a mean reading keeps it above 180. The only option that fits comfortably is 200 to 400.
A quicker estimate: SpaceX alone is about 96 and CASC about 45 — already about 141. Every other bar is under 30, and there are eight of them, so the rest add at most about 100 more. That puts the total between 200 and 250 without adding anything carefully. Remember to include the Other bar — it is easy to skip, and it is one of the bigger ones.
Q7.
What are you curious to know after looking at this graph?
Worldwide rocket launches by organisation for 2021, 2022 and 2023 — page 116.
Answer
This is an open question. Here are questions this graph genuinely provokes, and what data each would need.
Why does the USA launch so many more rockets than anyone else? Is it one company doing it, or the whole country? (The graph already hints: SpaceX alone is nearly half the world's launches in 2023.)
What happened before 2021 and after 2023? Was SpaceX always this far ahead, or is this a recent jump? You would need the same graph for 2015–2020.
Why did CASC dip in 2022 and recover in 2023?
Why did Arianespace fall so sharply? Did it stop using an old rocket before the new one was ready?
How many rockets does it take to put one satellite in orbit? A single rocket can carry many satellites, so launches and satellites are not the same count.
Which organisations are inside 'Other'? Together they launched more than ISRO, Rocket Lab and Expace combined.
How many launches failed? The graph counts launches, not successes.
Why this matters: the last two questions point at what the graph hides. A category called 'Other' and a count that mixes success with failure are both places where a careless reader can go wrong. Asking what a graph leaves out is as important as reading what it puts in.