Let the height of the building x metres.

Less lengthy shadow, Less in the height (Direct Proportion)

 So, 40.25 : 28.75 :: 17.5 : x    \( \Leftrightarrow\)    40.25 x x = 28.75 x 17.5

x =  \(\frac{28.75\times17.5}{40.25}\)

x= 12.5

There is a meal for 200 children. 150 children have taken the meal.

Remaining meal is to be catered to 50 children.

Now, 200 children \(\equiv\) 120 men.

50 children  \(\equiv\)  \(\left(\frac{120}{200}\times50\right)=30 men.\)

Le the required time be x seconds.

More metres, More time (Direct Proportion)

So,  0.128 : 25 :: 1 : x    \( \Leftrightarrow\)    0.128x = 25 x 1

x =  \(\frac{25}{0.128}=\frac{25\times1000}{128}\)

x=  195.31

So, Required time = 195 sec (approximately).

Let the required number of days be x.

Less men, More days (Indirect Proportion)

 So,  27 : 36 :: 18 : x    \( \Leftrightarrow\)    27 x x = 36 x 18

x =  \(\frac{36\times18}{27}\)

x= 24.

Let the required number of bottles be x.

More weavers, More mats (Direct Proportion)

More days, More mats (Direct Proportion)

4 x 4 x x = 8 x 8 x 4

x =  \(\frac{(8\times8\times4)}{(4\times4)}\)

x= 16.