Question

find the value of 5-5-5-5-5........191 times

Answer 1

$- 5 - 5 - 5 - 5 - 5 \times 191$
= -975

Answer 2

 5 + (– 5) + 5 + (– 5) + 5 ......

=  (5 – 5) + (5 – 5) + 5........

=   0 + 0 + 0 + 0 + 5......

=   5

Number of 5 in [5 + (– 5) + 5 + (– 5) + 5] is five.

AND five is an odd number.

and it's soluction is 5.

  5 + (– 5) + 5 + (– 5) + 5 + (- 5) ......

=  (5 – 5) + (5 – 5) + (5 – 5).......

=  0    

Number of 5 in [5 + (– 5) + 5 + (– 5) + 5 + (- 5)] is Six.

AND six is even number.

and it's soluction is 0.

We observed that, when number of five is odd answer = 5

and when it is even answer = 0

question ) 191

191 is an odd number then, answer = 5