40 cows eat 40 bags of husk in 40 days.
∴ 1 cows eat 40 bags of husk in 40 x 40 days.
∴ 1 cows eat 1 bags of husk in 40 x 40 / 40 days.

Correct Option: B

40 cows eat 40 bags of husk in 40 days.
∴ 1 cows eat 40 bags of husk in 40 x 40 days.
∴ 1 cows eat 1 bags of husk in 40 x 40 / 40 days.
∴ 1 cows eat 1 bags of husk in 40 days.

Cost of x meters ropes = Rs. d
∴ Cost of 1 meters ropes = Rs. d /x

Correct Option: A

Cost of x meters ropes = Rs. d
∴ Cost of 1 meters ropes = Rs. d /x
∴ Cost of y meters ropes = Rs. dy/x

∵ 8 m shadow means original height = 12 m
∴ 1 m shadow means original height = 12/8 m

Correct Option: A

∵ 8 m shadow means original height = 12 m
∴ 1 m shadow means original height = 12/8 m
∴ 100 m shadow means original height = (12/8) x 100 m
= (6/4) x 100 = 6 x 25 = 150 m

∵ Distance covered in 20 min = 5 km
∴ Distance covered in 1 min = 5/20 km

Correct Option: D

∵ Distance covered in 20 min = 5 km
∴ Distance covered in 1 min = 5/20 km
∴ Distance covered in 100 min = (5/20) x 100
= 5 x 5 = 25 km

Let the required weight be w kg.
Less length, Less weight (Direct proportion)
45 : 12 :: 171 : w

Correct Option: D

Let the required weight be w kg.
Less length, Less weight (Direct proportion)
45 : 12 :: 171 : w
∴ w = (12 x 171)/45 = 45.6 kg