ANSWERS  HURDLE 36 : QUADRATIC EQUATION + PROFIT AND LOSS
Below are the answers and and the solution of Hurdle 36. Those who got 25 questions correct in less than 15 minutes are
among the top 1 percentile.
Ans 1. 3
Ans 2. 4
Ans 3. 4
Ans 4. 15
Ans 5. 15
Ans 6. 13
Ans 7. 16
Ans 8. 16
Ans 9. 16
Ans 10. 6
Ans 11. 9
Ans 12. 9
Ans 13. 8
Ans 14. 8
Ans 15. 8
Ans 16. 8
Ans 17. 8
Ans 18. 16
Ans19. 22
Ans20. 22
Ans21. 22
Ans22. 10
Ans23. 40
Ans24. J , Ans25. D , Ans26. E , Ans27. A , Ans28. C , Ans29. B , Ans30. H
====================================================
SOLUTIONS OF SOME QUESTION
Solution1. As a^2.b +b^2.c +C^2.a >= 3abc
so we have 3abc>=30
so abc>=10
Solution2. As a^2.b +b^2.c +C^2.a >= 3abc
we have 3abc>=120 or abc>=40
as a.b>=10 , c>=4
Solution3. As a^2.b +b^2.c +C^2.a >= 3abc
we have 3abc>=150 or abc>=50
as a.b >=5, c>=10
Solution4. Let the cost of Rice be X per kg.
S.P at 32 % = 1.32 X per Kg
S.P at 15% = 1.15 X per Kg
Average S.P = 1.2 X per Kg.
(\Qty of Cheap/ Qty of expensive) =
(Price of expensiveAverage price)/ ( Avg. Priceprice of cheaper)
= (1.32X1.2X)/ (1.2X1.15X)= .12/.05
=12/5
so the two quantities are in ratio of 12:5
So the Qty sold at 32% profit = 51*12/17= 36
Alternatively can use mixture and allegation method.
Solution6. Let the cost of Rice be X per kg.
S.P at 4 % = 1.04 X per Kg
S.P at 7% = 1.07 X per Kg
Average S.P = 1.06 X per Kg.
(Qty of Cheap/ Qty of expensive) =
(Price of expensiveAverage price)/ ( Avg. Priceprice of cheaper)
= (1.07X1.06X)/ (1.04X1.06X)= .01/.02
=1/2
so the two quantities are in ratio of 1:2
So the Qty sold at 4% profit = 39*1/3= 13
The rest of the questions may be solved using the same method.
