In how many different ways can letters of the word ‘SECOND’ be arranged?

If $$ {x+3y-{2z\over 4}}=6$$ , $$ {x+{2\over 3}}(2y+3z)=33$$ and $$ {1\over 7}{(x+y+z)+2z=9}$$, then what is the value of $$ {46x+131y}$$?

After a discount of 20% Asmita bought an item for Rs.9600. Asmita sold it to other person and earned a profit of 18% on the original price. At what price other person bought the item?

Direction (66-70): What should come in place of the question mark(?) in the following number series?

10    11    13    21    69    ?

What approximate value should come in place of the question mark(?) in the following question.
635×455÷403=?

A number which, when increased by 123% becomes 3345. The number is—