#### 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 (a) 2 weeks (b) 3weeks?

2) How high was Plant B after (a) 2 weeks (b) 3weeks?

3) How much did Plant A grow during the 3^{rd} week?

4) How much did Plant B grow from the end of the 2^{nd} week to the end of the 3^{rd} 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.

#### Solution

1)

a. After 2 weeks, the height of plant A was 7 cm.

b. After 3 weeks, the height of plant A was 9 cm.

2)

a. After 2 weeks, the height of plant B was 7 cm.

b. After 3 weeks, the height of plant B was 10 cm.

3) Growth of plant A during 3^{rd} week = 9 cm − 7 cm = 2 cm

4) 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

5) 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.

6) 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.

7) At the end of the 2^{nd} week, the heights of both plants were same.