Self
Maths Puzzle
Numerical Ability
Number System
Find the smallest number in a GP whose sum is 42 and product 1728.
a)6 b)8 c)12 d)14
Read Solution (Total 2)
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- x+y+z=42, x.y.z=1728
in GP a, ar,ar^2,ar^3................
y^2=xz,
y^3=1728,so y=12
& xz=144,z=144/x
x+12+144/x=42
x^2-30x+144=0
we get,x=6,24
then z=144/24=6
x=6,z=6,y=12
so smallest no is 6
- 9 years agoHelpfull: Yes(1) No(0)
- mr.pimplikar,through the method in which u derived the numbers are not satisfying the given equations....
- 9 years agoHelpfull: Yes(0) No(0)
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