IIT JEE , AIEEE Forum - Mathematics , Algebra

vish0001

i faintly remember this question which came in I.P. university exam

do correct me if wrong

Q. if a , b , c are in AP

then (1+a ) , ( 2+ b ) , (1 + c) are in ::

(a) AP (b) GP (C) HP (D) NOT

i don't remember exactly.......somebody knows the full question please

joyfrancis

Hi.

Here is a shortcut.

Take a,b,c as 1,2,3

1+a=2

2+b=4

1+c=4

since 2,4,4 are neither in AP,GP or HP the ans is

(D)

elessar_iitkgp

Excellent solution joy.

vish0001

thanx yaar joyfrancis

raman_shadow

sorry joy but a,b,c r in AP. its given but 1,2,4 r in no case in AP.

the solution is still d). u can check by the method provided by joy

harshdeep89

hey Joy howz 1,2,4 in ap??

See, since a,b,c are in AP write b=(a+c)/2

the sereis becomes 1+a,2+(a+c)/2,1+c

now this could be veriofied as none of ap,gp,hp..

joyfrancis

oh yeah, i took it as a GP.
See the edited version