A and B are two heavy steel blocks. If B is placed on the top of A, the weight increases by 60%. How much weight will reduce with respect to the total weight of A and B, if B is removed from the top of A?

Correct Option

Let the weight of steel block A be $x$.

When block B is placed on top of A, the total weight increases by 60%. Therefore, the combined weight of A and B is:

Total Weight (A + B) = $x+0.60x=1.60x$

The weight of block B is the difference between the total weight and the weight of A:

Weight of B = Total Weight (A + B) - Weight of A = $1.60x-x=0.60x$

When block B is removed from A, the weight reduced is the weight of B, which is $0.60x$.

The question asks for the percentage reduction with respect to the total weight of A and B (which is $1.60x$).

Percentage Reduction = $\frac{\text{Weight of B}}{\text{Total Weight (A + B)}}\times 100$

= $\frac{0.60x}{1.60x}\times 100$

= $\frac{60}{160}\times 100$

= $\frac{3}{8}\times 100=37.5\mathrm{\%}$

Incorrect Options

Options 1 (60%), 2 (45.5%), and 3 (40%) are incorrect as they do not represent the accurate percentage reduction calculated relative to the combined weight of blocks A and B.