Two solution X and Y containing ingredients A, B and C in proportions a:b:c and c:b:a, respectively, are mixed. For the resultants mixture to have A,B and C in equal proportion it is necessary that:

• $\mathrm{b}=\frac{\mathrm{c}-\mathrm{a}}{2}$

• $\mathrm{c}=\frac{\mathrm{a}+\mathrm{b}}{2}$

• $\mathrm{c}=\frac{\mathrm{a}-\mathrm{b}}{2}$

• $\mathrm{b}=\frac{\mathrm{c}+\mathrm{a}}{2}$

Find the missing figure in the following sequence.

In triangle ABC, AB= 11, BC=61, AC=60, and O is the mid point of BC. Then AO is.

• 18.5

• 24.5

• 30.5

• 36.0

Area of three parts of a rectangle are given in unit of cm². What is the total area of the rectangle?

• 18

• 24

• 36

• 108

A students is free to choose only chemistry, onl biology or both. If out of 32 students, chemistry has been chosen by 16 and biology by 25, then how many students have chosen biology but not chemistry?

• 9

• 16

• 25

• 7

The lift (upwards forces due to air) generated by the wings and engines of an aircraft is:

• Positive (upwards) while landing and negative ( downwards) while taking off

• Negative (downwards) while landing are positive (upwards) while taking off

• Negative ( downwards) while landing as well as while taking off

• Positive (upwards) while landing as well as while taking off