Longest word in English lang

What is the longest word in the English language that can be produced from the ten letters below? No letter may be used more than once.

H T E R C I K F A O

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Decimal math pblm

Solve the below math::
What is the value of 3/8 + 5/16 as a decimal??

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Diff % of Apples&oranges

At the end of the day one market stall had 16 apples and 48 oranges left. Another market stall had 36 apples and 24 oranges left. 
What is the difference between the percentages of apples left in the two market stalls?

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weight of marble

A marble statue is being carved by a sculptor. In the first week 35% is cut away, in the second week 20% of the remainder is cut away and in the third week 25% of the remainder is cut away and polished to produce the final statue. The weight of the final statue is 48.75 lbs. 
What was the weight of the original piece of marble?

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Missing section

A  G  D  K  G  R  K
F   R  N  L  A  B   D
L   B  B  F   F  N  N
K  N  R  A   L  D  B
D  D  G  G  K  K  R
N  K   A            L  G
B   L   F            F   A

Which is the missing section?

1)   D   R           2) R   D      3)  D   R         4) R   D
       B   N               N   B           N   B             B   N

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Probability math pblm

You have two bags each containing six balls. The first bag contains balls numbered 1 to 6 and the second bag contains balls numbered 7 to 12. A ball is drawn out of bag one and another ball is drawn out of bag two. 
What are the chances that at least one of the balls drawn out is an odd-numbered ball?

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pair of anagrams

Identify the pair of anagrams from the list of words below.
corniest, esoteric, serotine, ordinate, obtained, monsters, proteins, antipode, bisector, rationed, ptomaine, senorita, baritone

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