1. Consider the following statements with reference to Feldspar mineral :

  1. Half of the earth's crust is composed of feldspar
  2. It has light cream to salmon pink colour
  3. Magnesium is a common element in all types of feldspar

Which of the statements given above is/are correct?

 


1. How many terms of the series 1+3+5+ 7+ ... amount to a sum equal to 12345678987654321?

  


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