IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE O - Level => Math => Topic started by: holtadit on April 02, 2010, 02:48:18 pm

Title: Maths help... u know who I am :D
Post by: holtadit on April 02, 2010, 02:48:18 pm

Question 5  b  iv

The MS says 1/18   how is this possible ?

Question 10  b i                 -------> How do u get the formula ?
Question 10 b iii a              -------->  MS says 16, how ? 




The MS and Question paper are attached..

Title: Re: Maths help... u know who I am :D
Post by: astarmathsandphysics on April 02, 2010, 03:20:05 pm

b)i)A=5xy=80 so xy=16 and y=16/x
P=10x+2y =10x+2*16/x=10x+32/x
b)iii)a) xy=16  and x=y so x^2=16 and x=y=4
P=10x+32/x=10*4+32/4=48

Title: Re: Maths help... u know who I am :D
Post by: astarmathsandphysics on April 02, 2010, 03:23:42 pm

I dont have the ms can you upload it?

Title: Re: Maths help... u know who I am :D
Post by: Ghost Of Highbury on April 19, 2010, 06:26:41 pm

5 b iv ) The options are Sarah gets 1 and Terry gets (1+4) = 5
                                       
                                     or
                                 Sarah gets 2 and terry gets (2+4) = 6

The probability now

for the first Sarah gets 1 = 1/6  ; Terry gets 5 = 1/6 . Total = because of "And" --> 1/6 * 1/6 = 1/36

for the second one Sarah gets 2 = 1/6 ; Terry gets 6 = 1/6. Total = because of "And" --> 1/6 * 1/6 = 1/36

Due to the "or" we add the two sets up = 1/36 + 1/36 = 2/36 = 1/18