Question

For an experiment in Botany, two different plants, plant A and plant B were grown under similar laboratory conditions. Their heights were measured at the end of each week for 3 weeks. The results are shown by the following graph. 

1. How high was Plant A after (i) 2 weeks (ii) 3weeks? 
2.  How high was Plant B after (i) 2 weeks (ii) 3weeks? 
3.  How much did Plant A grow during the 3rd week? 
4.  How much did Plant B grow from the end of the 2nd week to the end of the 3rd week? 
5.  During which week did Plant A grow most? 
6.  During which week did Plant B grow least? 
7.  Were the two plants of the same height during any week shown here? Specify.

Answer 1

(a)
(i) After \(2\) weeks, the height of plant A was \(7\) \(cm\).
(ii) After \(3\) weeks, the height of plant A was \(9\) \(cm\).

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(b)
(i) After \(2\) weeks, the height of plant B was \(7\) cm.
(ii) After \(3\) weeks, the height of plant B was \(10\) cm.

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(c) Growth of plant A during 3rd week = \(9 \;cm - 7\; cm\) = \(2\) \(cm\)

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(d) Growth of plant B from the end of the \(2\)nd week to the end of the \(3\)rd week
= \(10 \;cm - 7 \;cm = 3 \;cm\)

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(e) Growth of plant \(A\) during \(1\)st week = \(2\; cm - 0 \;cm = 2 \;cm\)
Growth of plant \(A\) during \(2\)nd week = \(7\; cm - 2 \;cm = 5\; cm\)
Growth of plant \(A\) during \(3\)rd week = \(9 \;cm - 7 \;cm = 2 \;cm\)
Therefore, plant \(A\) grew the most, i.e. \(5\) \(cm\), during the \(2\)nd week.

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(f) Growth of plant \(B\) during \(1\)st week = \(1 \;cm - 0 \;cm = 1 \;cm\)
Growth of plant \(B\) during \(2\)nd week = \(7 \;cm - 1 \;cm = 6 \;cm\)
Growth of plant \(B\) during \(3\)rd week = \(10 \;cm - 7\; cm = 3 \;cm\)
Therefore, plant \(B\) grew the least, i.e. \(1\) \(cm\), during the \(1\)st week.

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(g) At the end of the 2nd week, the heights of both plants were same.