[email protected] wrote:Which of the following is equal to (0.9998)^2 ?
A) 0.999500
14
B) 0.999502
34
C) 0.999600
04
D) 0.999600
64
One option is to apply some algebra to this, but I think it's actually faster to recognize that we can perform a TINY PORTION of the multiplication and get the correct response.
Notice that the
LAST TWO digits of the answer choices differ. So, we'll perform only the multiplication that affects those last two digits.
First, we'll multiply the
8 to get the following:
Notice that we didn't bother completing the entire multiplication.
Then, add with the customary 0 in the digits place and multiply the
9 to get the following:
IMPORTANT: since the next step will be to add 0's in the
last two places before we begin multiplying, we know that all steps beyond this point WILL NOT affect the last 2 digits of the final answer. So, we'll stop here and add our products to get the following:
As you can see the correct answer is
C
Cheers,
Brent
