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Two samples of sizes 60 and 90 have 52 a...

Two samples of sizes 60 and 90 have 52 and 48 as the respective A.Ms. and 9 and 12 as the respective S.Ds. Find the A.M and S.D. of the combined sample of size 150.

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UNITED BOOK HOUSE-MODEL QUESTION PAPERS-SET 1-EXERCISE
  1. If a,b,c are in G.P and x,y are the arithmetic mean of a and b aand b,...

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  2. Prove that the straight lines ax+by+c=0,bx+cy+a=0and cx+ay+b=0 are con...

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  3. Find the equation of the straight line which divides perepndicularly t...

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  5. 3x+y=5 and x+y-1=0 are the equations of two diamters to the circle,whi...

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  6. Evaluate :lim(xrarr1)(x+x^2+x^3+...+x^n-n)/(x-1)

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  7. If sqrt(1-x^4)+sqrt(1-y^4)=k(x^2-y^2),show that y1=(xsqrt(1-y^4))/(ysq...

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  8. Prove that the cpmpound statement “If x and y are odd integers, then x...

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  9. Prove by method of contradiction that sqrt5is an irrational number

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  10. 6 boys and 6 girls occuppy seats ina row at random.What is the probabi...

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  11. Two samples of sizes 60 and 90 have 52 and 48 as the respective A.Ms. ...

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  12. Prove that tan6^@tan42^@tan66^@tan78^@=1

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  13. Solve :sin^3thetacostheta-cos^3thetasintheta=1/4

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  14. Draw the graph and find the solution (common) region of the following ...

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  15. Solve 12ix^2-x+6i=0

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  16. Find the sum upto nth term :1+4/5+7/5^2+10/5^3+.....

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  17. How many ways of selecting 4 letters from the words EXAMINATION.

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  18. If the length of the double ordinate of a parabola y^2=4ax is 8a.Prove...

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  19. If the eccentric angles of the any two points P,Q on the ellipse x^2/a...

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  20. If the hyperbola x^2/a^2-y^2/b^2=1 passes through the interesecting po...

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