Class 8 Reading Line Graphs — practice questions with answers
Coordinate Geometry · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
1. In a line graph, which axis (horizontal or vertical) usually shows the quantity that depends on the other?
AThe vertical axis (y-axis)
BThe horizontal axis (x-axis)
CNeither axis
DBoth show the same thing
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Answer: A) The vertical axis (y-axis)
The independent variable (like time) is plotted on the horizontal x-axis, while the dependent quantity is read on the vertical y-axis.
2. A shop's daily sale (in Rs) is plotted: Mon 4000, Tue 3000, Wed 5000, Thu 2000. On which day were sales the lowest?
AThursday
BTuesday
CMonday
DWednesday
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Answer: A) Thursday
The smallest value is 2000, which is on Thursday.
3. A line graph shows the number of bicycles sold by a shop in Pune over five months: Jan 30, Feb 45, Mar 45, Apr 60, May 50. What was the total number of bicycles sold in these five months?
A460
B205
C230
D255
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Answer: C) 230
30 + 45 + 45 + 60 + 50 = 230 bicycles.
4. Two line graphs share the same axes: Plan A charges Rs 200 fixed plus Rs 0 per km (a flat line at 200), while Plan B starts at Rs 0 and rises by Rs 4 per km. At how many km do the two plans cost the same amount?
A45
B55
C100
D50
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Answer: D) 50
Set 200 = 4k, so k = 4200=50 km. The lines meet at 50 km.
5. A line graph shows two pipes filling a tank (litres vs minutes). Pipe A's line rises from (0,0) to (10, 50). Pipe B's line rises from (0,0) to (10, 80). If both pipes are opened together, how many litres will be in the tank after 10 minutes?
A145
B260
C130
D115
Show answer
Answer: C) 130
After 10 min Pipe A gives 50 L and Pipe B gives 80 L. Together = 50 + 80 = 130 L.