Management Aptitude Test 2014 Paper

(a) Let the cost of components 3x, 4x, 5x and 6x, respectively of A, B, C and D.
Change of cost in component A
= 3x +

3x×10

100

=

33

100

x
Change of cost in component B
= 4x -

4x×20

100

=

16

5

x
Change of cost in component C
= 5x -

5x×30

100

=

7

2

x
Change of cost in component D
= 6x +

6x×40

100

=

42

5

x
Now, total cost before change
= 3x + 4x + 5x + 6x = 18x
Total cost after change
=

33

10

x+

16

5

x+

7

2

x+

42

5

x =

184

10

x
∴ Total change in cost =

184

10

x - 18x =

4

10

x = 0.4x
∴ Percentage change =

0.4x

18x

× 100 =

40

18

=

20

9

= 2.22%