you should think of these multiplications as though the decimal point has moved.
in fact, this is precisely what has happened, as both statements involve multiplication by powers of 10 -- which serves to move the decimal point while leaving the digits themselves unaffected.
here's the deal:
you are interested in the hundredths place of the original number 'd'. to wit, let's write 'd' as a succession of decimal places:
d = XXXXXX.XXXX...
in this version, the orange digit is the one in which you're interested.
statement (1) concerns the number 10d, not d. when you multiply by 10, the decimal point is shifted to the right by one spot, so that the ones digit becomes the new tens digit and so on. so, with 'd' represented as above, you can write
10d = XXXXXXX.XXX...
according to statement (1), then, the orange digit is 7, so statement (1) is sufficient.
statement (2) concerns the number d/10, not d. when you divide by 10, the decimal point is shifted to the left by one spot, so that the tens digit becomes the new ones digit and so on. so, with 'd' represented as above, you can write
d/10 = XXXXX.XXXXX...
according to statement (2), then, the orange digit is 7, so statement (2) is sufficient.
hth.
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
