manhattan187 really explained it technically. Thanks a lot cos I got an idea from that. GMAT's unusual way of testing the too fundamental!

Now lemme humbly share to all how I just nailed that elementary arithmetic with a market place knowledge.

,100 cents make one dollar. 10 cents make a dime.

how many dimes are in a dollar?

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you nailed it! 10! ten dimes are in one dollar.

now what is the ratio of dime to dollar?

is it 10?

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1/10! you nailed it!

You know that 10dimes make a dollar. right? what does it mean to say ratio of one dime to one dollar? I mean in literal economic sense. (tip: 10/2 means 10 things is being shared equally by two persons. so it means how many 2s do u get in a 10?. answer is 5two.)

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So the ratio of one dime to one dollar is dime/dollar. i.e. how many dollars do you get in a dime?

... of course you don't get up to a dollar in a dime.

you just get (1/10) dollars.

PS: still kudos to us in the annoying tic question for wrongly solving to get 2/15 and rightly use our commonsense to know that since you should get too many tocs in a freaking tic, therefore the answer must be more than one. So u quickly guessed by choosing the option that inverts what you've got from a good albeit imperfect thought process knowing that time is running out.