Area of Rectangle

[toponlinetool]

Can anyone please help in solving following problem? I am a little bit confused about how to solve these types of questions. From where to start & what to assume?
If the length and breadth of a rectangle are increased by a% and b% respectively, then the area will be increased by
(A) (a-b+2ab/100)%
(B) (a+b+2ab/100)%
(C) (a+b+ab/100)%
(D) (a-b+ab/100)%

 

[hoosie]

Let L = initial length, W = initial width Initial area = ?

If L is increased by a% how do we write the new length in terms of L?
Hint: Consider an example with numbers: increase 20 by 5%
5% of 20 = 1/20 × 20 = 1 20 is increased to 21 We can write 20 +(5/100)20 = 21)

If W is increased by b% how do we write the new width in terms of W?

Using new length and new width are you able to write an expression for the final area?
Remember this is the final area - you have to work out the increase in area and then the % increase in area.

 

[toponlinetool]

Let L = initial length, W = initial width Initial area = ?

If L is increased by a% how do we write the new length in terms of L?
Hint: Consider an example with numbers: increase 20 by 5%
5% of 20 = 1/20 × 20 = 1 20 is increased to 21 We can write 20 +(5/100)20 = 21)

If W is increased by b% how do we write the new width in terms of W?

Using new length and new width are you able to write an expression for the final area?
Remember this is the final area - you have to work out the increase in area and then the % increase in area.

Thanx hoosie..I liked your way of explaination.