Concrete slabs

[Woozler]

The cost of a square concrete 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 meters thick?

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

Edit: corrected

[Bharat]

Hi Woozler,
It appears that there is some typographical error in statement 1: "....quare slab 2 meters long and 0.2 m long...." (both are lengths?)

Otherwise the difference in price of two slabs is sufficient to answer the question. So statement 2 alone is sufficient here.
Regards,
Bharat

[Woozler]

Could you explain why it is sufficient? I am not really sure how we can go from "$160 more" to "this is the cost of the slab"

[Bharat]

Hi Woozler,
As per given information: cost = k*t*(l^2). (here is k is a proportional constant).
from #2: 160 = k*0.2*(2^2) - k*0.1*(2^2)
from here we can solve for k.
Put k back in cost formula & plug in t = 0.1, l = 3 to get the cost.

Let me know if you have further questions.
Regards,
Bharat.

[Woozler]

Ah, thanks. I'm not very familiar with the idea of proportional costs/ratios/whatever. Didn't know that.