Latest TCS Aptitude Question SOLUTION: 1-2+3-4+5……..-98+99 =

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(#M40012516) TCS question Keep an EYE

1-2+3-4+5……..-98+99 =

Asked In TCS Arpit (11 years ago)

Unsolved Read Solution (8)

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Read Solution (8) :

chandani  (11 years ago)

ans is 50.
as 1-2+3-4+5-6+7-....-98+99
can be written as
=(1+3+5+7+....+99)-(2+4+6+8+...98)
=(1+3+5+7+....+99)-2*(1+2+3+..+49)
=(1+3+5+7+....+99)-2*49*50/2
(1+3+5+7+....+99)-2450
=2500-2450 (as it is in AP as 1 1st term 99 last term)
50 ans

Is this solution Helpfull? Yes (43) | No   

udit narayana  (11 years ago)

1-2+3-4+5-6+......97-98+99

-1+(-1)+(-1)+....+99
=-49+99=50

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Akshay Bansal  (11 years ago)

ans 50.
50*50 - 50*49 = 50 .

Is this solution Helpfull? Yes (4) | No   

vivek garg  (11 years ago)

my ans is 50

Is this solution Helpfull? Yes (3) | No   

seraj (NIET)  (11 years ago)

ans= 100
becouse u can break it in two part
1+3+5........+99
and -2-4..............-98
and now apply the A.P. formula and get answer

Is this solution Helpfull? Yes (2) | No (6)  

tanushri godha  (11 years ago)

70....
99-29=70

Is this solution Helpfull? Yes (1) | No (12)  

niki  (11 years ago)

ans is 99.

Is this solution Helpfull? Yes | No (9)  

pradeep  (11 years ago)

ans is 50

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