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The question is followed by two statements I and II.

Mark

1. if the question can be answered by any one of the statements alone, but cannot be answered by using the other statement alone.
2. if the question can be answered by using either statement alone.
3. if the question can be answered by using both the statements together, but cannot be answered by using either statement alone.
4. if the question cannot be answered even by using both the statements together.

A line graph on a graph sheet shows the revenue for each year from $1990$ through $1998$ by points and joins the successive points by straight-line segments. The point for revenue of $1990$ is labelled A, that for $1991$ as B, and that for $1992$ as C. What is the ratio of growth in revenue between $1991-92$ and $1990-91?$

1. The angle between AB and X-axis when measured with a protractor is $40^{\circ}$, and the angle between CB and X-axis is $80^{\circ}$.
2. The scale of Y-axis is $1 \; \text{cm = Rs.} \; 100$

option A is correct.

X' parallel to X-axis and B1C1 parallel to B2C2

we just need to know ratio of growth. for ration of growth we need ratio of line ABand CB. CB can be C1B1 or C2B2. becuase only angles are given ..not the location of points (if we take statement I for answer)

but ratio between lengths of C1B1 and C2B2 is equal because trianlge AB1C1 and AB2C2 are similar(by AAA rule)

AB1/C1B1 = AB2/C2B2

=> AB1/AB2 = C1B1/C2B2

so ratio cant be changed by their(points ) location

I guess as there is no need to use statement II 1 cm =100 rs as ratio has no unit.

only statement I enough for answering the question.

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