NP Decimals

[Abdulla]

(0.0036)(2.8) / (0.04)(0.1)(0.003) = ?

Can someone give us a quick technique to solve this problem ??

Thanks

[DanaJ]

Just try and eliminate step by step:
0.0036/0.1 = 0.036
0.036/0.04 = 0.9
0.09/0.003 = 30
So you're left with 30*2.8 = 28*3 = 84.

[Bidisha800]

getting 840

[sureshbala]

Just try and eliminate step by step:
0.0036/0.1 = 0.036
0.036/0.04 = 0.9
0.09/0.003 = 30
So you're left with 30*2.8 = 28*3 = 84.

Look at the bold statement....

It has to be 0.9/0.003 = 300.

So the answer will be 300(2.8) = 840

[DanaJ]

Funny how I copied my own answer incorrectly....

[[email protected]]

Hi All,

We're asked for the value (0.0036)(2.8) / (0.04)(0.1)(0.003)

When dealing with lots of decimals, you might find it easiest to deal with one 'small calculation' at a time. It's worth noting that you can multiply the 'top' and 'bottom' of a fraction by the same number and the value won't change. For example, with 1/2 if you multiply the numerator and denominator by 5, you end up with 5/10 (which still equals 1/2). To remove decimals from a fraction, it's often easiest to multiply by 10 or 100 or 1000, etc.

(0.0036)(2.8) / (0.04)(0.1)(0.003)

To start, let's multiply by 1000 and rewrite the 'scariest' parts of the fraction...

(3.6)(2.8) / (0.04)(0.1)(3)

Next, let's multiply by 10....
(36)(2.8) / (0.04)(1)(3)

Finally, let's multiply by 100....
(36)(280) / (4)(1)(3) =
(36)(280) / (12) =
(3)(280) / 1 =
At this point, you can technically stop working. You know that the result will be greater than 280 and there's only one answer that 'fits'...

Final Answer: A

GMAT assassins aren't born, they're made,
Rich