Question

whats 1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9

Answer 1

Answer:

90 is your answer

Step-by-step explanation:

first I just added all similar numbers together, then I added the answers of all the similar numbers together one-by-one, finally we find our answer, 90

Answer 2

Answer:

Its 90

Step-by-step explanation:

I used a calc.....

1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 + 7 + 8 + 8 + 9 + 9= 90