Exams

let ABCD be the given parallelogram 

area of parallelogram ABCD = 2 x (area of triangle ABC) 

now a = 30m, b = 14m and c = 40m

 s=1/2 x (30+14+40) = 42 

Area of triangle ABC = ss-as-bs-c  

= 4212282= 168sq m 

area of parallelogram ABCD = 2 x 168 = 336 sq m

All locks are bangles + All bangles are cars = A + A = A
= All locks are cars => Some cars are locks.
Hence conclusion (a) follows.
All keys are locks + All locks are bangles = A + A = A
= All keys are bangles => some bangles are keys.
Hence conclusion (b) follows.
All keys are bangles + All bangles are cars = A + A = A
= All keys are cars => Some cars are keys.
Hence conclusion (C) follows.

Thus all a, b and c follows.

Let original length = x and original breadth = y.

Original area = xy. 

New length = x/2 and New breadth=3y 

New area = 32xy 

Therefore,  Increase in area = New area-original area = 32xy-xy=12xy 

Therefore,  Increase % = increase in area original area*100=12xyxy*100=50 %