## Friday, December 21, 2012

### IMO Answer Key SET B

IMO Answer Key SET B held on 20.12.12

Anonymous said...

Sir Some Answers Are Wrong Which I Am Telling You In class 8 imo
Question 19- There Is No Word That Can Be Formed From G,R,A And P.Hence Answer Should Be Option b) M
Question 23- Minimum Amount Would Be Of Package X
The Respective Amounts Are
W- 27
X- 20.40
Y- 32.5
Z-24.5
Hence Answer Should Be Option b)
Question 35-
x+1/x = Root 5
(x+1/x)Whole Square = Root 5 Whole Square
x2+1/x2+2 = 5
x2+1/x2 = 3
Now Again Squaring Both The Sides
x4+1/x4+2 = 9
x4+1/x4 = 7

Anonymous said...

A lot of wrong answers in class 9 IMO.

Anonymous said...

Sir Why Aren"t You Correcting The Answer Keys.
I Had Provided The Explanation To You Already For Class 8 IMO Set B.
For Question 35 Another Method Is
x+1/x = Root 5
x2+1 / x = Root 5
x2+1 = Root 5 * x
x2-Root5x +1 = 0
Use Quadratic Formula To Solve It
Root 5+Square Root (5-4) / 2
Root 5+1 / 2
And Root 5-1 / 2
Substitute It In Expression x4+1/x4
We Will Get The Result As Follows
x = 6.95