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Maths, Addmaths and Statistics: Post your doubts here!

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The b part is connected to part a !! the total time of the journey is 7.5 hours ryt !! for the first part of 5 hrs journey she travelled 150 km ~!! for the next 2.5 hours she will travel at 20 km/ h !! so distance would be = 20*2.5 = 50 km !! so now the average spped for the whole journey would equal = total distance / total time taken

which will be = 200/7.5 = 26.67 km / h !!

i haven't checked the mark scheme or anything + i am not sure i am ryt !! i tried to help !! do tell me whether its the rite answer or not :)

Please answer my question
 
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The b part is connected to part a !! the total time of the journey is 7.5 hours ryt !! for the first part of 5 hrs journey she travelled 150 km ~!! for the next 2.5 hours she will travel at 20 km/ h !! so distance would be = 20*2.5 = 50 km !! so now the average spped for the whole journey would equal = total distance / total time taken

which will be = 200/7.5 = 26.67 km / h !!

i haven't checked the mark scheme or anything + i am not sure i am ryt !! i tried to help !! do tell me whether its the rite answer or not :)
yes you are right! i did not look at the first part while doing the second part i have got it now and thankyou . :)
 
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answer quickly

(a) 1/2*u*20 =10u= D (Triangle area) at T=20
total distance left = 2D-D=D
u*x=D
u*x=10u
x=10

T= 20+10 = 30

(b) You will get the value of 100 .. by simple logic.

as the deceleration is half of the first part. so u/20 * 1/2 = u/40

it took 20 seconds to reach u. so it will take 40 seconds to reach 0 from u.

40+60=100s

100s pe speed zero hojati hai ..

100 - Time at which speed=u/4.

Time=Speed/Acceleration
Time=(u/4) / (u/40)
= u/4 * 40/u
= 10s

100-10=90s.
 
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People please answer How to convert a Speed Time graph into A Distance Time graph!
 
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12 b) BA = 3a - 2c
if u take out 3/2 common from BA u'l get
BA= 3/2 ( 2a - 4c/3) this means BA = 3/2 OP
this shows BA = kOP
thus BA and OP are parallel

12 c) if u take BA and OP as base of each triangles, u'll see that height of each triangles are same and so when you'll find ratio of areas u'll see that it is actually the ratio of their base.

0.5 x BA x h / 0.5 x OP x h
now replace BA wid 3/2 OP
ratio of areas will be 3/2

do tell me if I am ryt ?

20 c . ratio of volumes of X and C = 27 / 125
if X is 27 out of 125 then Y will be (125 - 27)
so ratio will be 27 : 98
 
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12(b) BA = 3a -2c
OP= 2a- 4c/3

take comman= BA=3(a-2c/3)
OP=2(a-2c/3)

since the vectors are in the form k(x+y) they are parallel. as long as they are multiples of the same vector they are always parallel.

12(c) Sorry I have no idea about this one.

s08_qp_1.pdf

18 (b) nothing can be simpler than this! just divide by 10^12 so 1.5 x 10^8/10^12

answer will be 1.5 x 10^-4 or 1.5/10^4

24 (a) (i)

Number of Books = x
Frequency = f

formula for mean is sum of fx/sum of f.

so take fx
0*10+1*1+2*8+3*3+4*6... and so on.

and then divide it by sum of all the frequencies which is mentioned in the question (50 students)

you should now get the answer! won't calculate it .. will leave it to you.


s09_qp_1.pdf

15 (c) range is always the largest value - smallest value .. so in this case convert everything to seconds first .. 240-75 = 165 seconds .. which equals 2 minutes 45 seconds.

w09_qp_1.pdf

18 (b) ii its again ratios of areas .. which I don't know. Sorry.
 
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