Data Sufficiency

soni_pallavi wrote:Q1) The cost of a square slab is proportional to its thickness and also proportional to the square of its length.What is the cost of a square slab that is 3 meters long and 0.1 meter thick?

1)The cost of a square slab that is 2 meters long and 0.2 meter thick is 160$ more than the cost of a square slab that is 2 meters long and 0.1 meter thick.

2)The cost of a square slab that is 3 meters long and 0.1 meter thick is 200$ more than the cost of a square slab that is 2 meters long and 0.1 meter thick.

Thanks

Let us assume that C = Cost, T = thickness, L = Length, k = constant of proportionality
C = k * L * T²

(1) The cost of a square slab that is 2 meters long and 0.2 meter thick is $160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.
C = k * 2 * (0.2)² = 0.08k
C = k * 2 * (0.1)² = 0.02k

0.08k = 160 + 0.02k
0.06k = 160
k = 160/0.06 = 1000
Substitute this value of k in C = k * L * T²; SUFFICIENT.

(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is 200$ more than the cost of a square slab that is 2 meters long and 0.1 meter thick, which is the same as statement but with different values; SUFFICIENT.

The correct answer is D.