Ganita Manjari · Class 9 · Part II · Chapter 10

Class 9 Maths Ganita Manjari Chapter 10 Exercise 10.4 Solutions

Both questions are about stacked bars: reading the IUCN Red List column chart and drawing two stacked bar charts of a bowler's wickets.

Last updated 6 October 2026

2Questions
3Diagrams
Ch 10How Quantities Combine: Understanding Data

How to read and draw stacked bars

segment length = end of segment − start of segment

Find the total The whole bar, from 0 to its end, is the total of all its parts.
Find one part Subtract where the part starts from where it ends. The end alone is not the value.
Compare Totals are easy to compare. Parts that do not start at 0 are harder, so read them with care.
Draw Place the segments one after another from 0, using the same scale for every bar.

Stacked bar: one bar made of segments joined end to end, one segment for each part.

Segment: one coloured part of a stacked bar, such as Test wickets at home.

Total: the length of the full stacked bar, the sum of all its segments.

Reading a stacked column chart

Question 1: Species on the IUCN Red List

Answer: total, ≈ 1,000, small rise

Question: The stacked column chart shows the number of animal species on the IUCN Red List, by class, in 2007, 2010, 2013, 2016 and 2019. (i) What does 14,234 on top of the 2019 column represent? (ii) Approximately how many reptile species were on the list in 2016? (iii) Which classes had a relatively small increase between 2007 and 2019?

Part (i) · What does the number on top of a column mean?

In a stacked column, all the classes (mammals, reptiles, birds, insects, amphibians, molluscs, fish and others) are placed one on top of another. So the top of the column shows the total of all of them.

Q1 · the number on top of each column is the total of all classes

So 14,234 is the total number of animal species on the Red List in 2019, counting every class together. In 2007 the total was 7,851, so the list grew by 14,234 − 7,851 = 6,383 species. As a percentage:

63837851 × 100 ≈ 81.3%

Part (ii) · Reptile species in 2016

A part of a stacked column is read from the length of its segment, not from where it ends. Find the reptile colour (dark red) in the 2016 column. It starts where the mammals segment ends, and it ends higher up.

reptiles ≈ top of the reptile band − bottom of the reptile band

Reading the chart, the band is about 1,000 tall, so there were about 1,000 reptile species in 2016. This is an estimate read from a picture, so an answer a little above or below 1,000 is fine.

Part (iii) · Which classes grew only a little?

Compare the thickness of each coloured band in 2007 and in 2019. Some bands become much thicker (reptiles, insects, fish and others). The bottom bands, mammals and birds, look about the same thickness in both years, so these classes saw a relatively small increase.

Check by comparing each band's thickness in the 2007 and 2019 columns. The band that looks almost unchanged is the one with a small increase.

(i) 14,234 is the total of all classes in 2019. (ii) About 1,000 reptile species in 2016. (iii) Mammals and birds rose only a little (read from the chart, so approximate).

Drawing stacked bars

Question 2: Wickets taken by a bowler

Answer: 194 / 292; 234 / 149 / 103

Question: The table shows wickets taken by a bowler in international cricket till 2025. Complete the two stacked bar charts: (i) total wickets at home and overseas, split by format; (ii) total wickets in each format, split by home and overseas.

Step 1 · Write the table with totals

	Test	ODI	T20	Total
Home	62	100	32	194
Overseas	172	49	71	292
Total	234	149	103	486

Home total: 62 + 100 + 32 = 194. Overseas total: 172 + 49 + 71 = 292. Check: 194 + 292 = 486, and 234 + 149 + 103 = 486 as well.

Part (i) · Home vs overseas, split by format

Each bar is one row. Draw segments one after another from 0. Home: Test from 0 to 62, ODI from 62 to 162, T20 from 162 to 194. Overseas: Test from 0 to 172, ODI from 172 to 221, T20 from 221 to 292.

Q2(i) · the overseas bar is longer, so more wickets came overseas

Part (ii) · Each format, split by home and overseas

Now each bar is one column of the table. Test: Home from 0 to 62, Overseas from 62 to 234. ODI: Home from 0 to 100, Overseas from 100 to 149. T20: Home from 0 to 32, Overseas from 32 to 103.

Q2(ii) · Test is the format with the most wickets in total

(i) Home 194 and Overseas 292, each split into Test, ODI and T20. (ii) Test 234, ODI 149 and T20 103, each split into Home and Overseas.

Answers at a glance

Totals are read at the end of a stacked bar. A single part is read from the length of its segment.

Question	What is asked	Where to look	Answer
Q1	Species on the Red List	Top of column, reptile band, band thickness	14,234 is the 2019 total; about 1,000 reptiles; mammals and birds grew little
Q2	Complete two stacked bars	Table totals	Home 194, Overseas 292; Test 234, ODI 149, T20 103

Source of the questions: NCERT, Ganita Manjari, Grade 9, Part II, Chapter 10, Exercise 10.4. The solutions, explanations and diagrams on this page are our own working.