1hey bhaiyya anuj is still online and is showing that last onlin 00:40am 28-01-09 check out that problem of this site bhaiyya
7 Answers
62number is of form
7n
7n+1
7n+2
7n+3
7n+4
7n+5
7n+6
the square is correspondingly of the form
7n
7n+1
7n+4
7n+2
7n+2
7n+4
7n+1
if we need the sum of 2 such to be 7n then both have to be of the form 7n
hence the probability is 1/49
16216x2+8(a+5)x-7a-5
for strictly above x axis,
D<0
hence
64(a+5)2+4.16.(7a+5)<0
a2+10a+25+7a+5<0
a2+17a+30<0
(a+8.5)2<42.25
now the second part can be dealt quite easily...
for |a+8.5|<6.5
-15<a<-2
hence a can take these values from -14 to -3 which are 12 in number
thus 12/20 = .6
check for mistakes :)
1its given a belongs to [-20,0]
it doesnt say only integers!!! dont u need to take into account all real values of a in the given range?????????
then ur answer will defer.....
1yup atman then the answer will change...
You are right to have pointed out that...
make necessary changes according to that
@eureka... there will be 7.7 cases... a can be picked in 7 ways so can b be...
24sorry attman,,, forgot to give it.........a belongs to integers...............