CDS Government Jobs Exams Logical Reasoning Blood Relations

If r and s are the real numbers such that r+s=1 and s lies between 0 to 1, then what is the maximum value of product rs ?

Read Solution (Total 2)

maximum value of rs=.25

rs=r(1-r)=r-r^2
to find point of maximum , take derivative and equate to 0.
2r=1

r=1/2
since r+s=1
s=1/2

max. of product rs=.5*.5=.25
12 years agoHelpfull: Yes(14) No(1)

1/4 by taking the derivative of the given function
11 years agoHelpfull: Yes(2) No(0)

CDS Other Question

A wall measures 40m by 30m contains a window of size 15m by 10m. If the wall is hit by four stones, assuming that each stone hits the wall in a random position, independently of other stones, what is the probability that every throw hits the window ? If x(x+y+z)=9,y(x+y+z)=16 and z(x+y+z)=144, then x=?