Dear felippemed,
I'm happy to respond. This is a question crying out for estimation!

First, we will estimate: it's about 1000 x 1000 x 100, which would be 100,000,000. Choices (A) & (B) are way to small, and choice (E) is way too big, but (C) & (D) are plausible. Right away, if we were shoot on time, we could guess from the two remaining answers, and our odds of advancing would be excellence.

Do not, do not, do not under any circumstances perform the multiplication. Here's another trick. Look at the final digit of each factor: 2 in the hundreds place, 6 in the tens place, and 1 in the tens place. Multiply these: we get 12, or in other words, a final digit of 2 in the ten thousands place. From this, we immediately see that the answer must be (C), not (D).

Does all this make sense?

Mike
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So We can say for this Rectangular ( Cuboidal Shape )

Height = 110 cm
Length = 1200 cm
Breadth = 960 cm

Now , count the number of zeroes ( 4 in this case ) =====> Possible answer options (C) and (D)

Next find the last non zero digit , in this case it will be -

1 x 2 x 6 => 2 =====> Possible answer options (A) , (C) and (D)

Now combine those answer choice (C) is correct....


Hope this helps !!
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The amount of water in the tank when the water level is 10 centimeters below the top of the tank is:

1,200 x 960 x 110 = 126,720,000 cubic centimeters

Answer: C
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