percentage

There were 20% more oranges than grapes. 

\(o = (1+0.2)g\) 

When 126 fruits were added, the oranges were increased by 10% and the grapes increased by 9%

\((1+0.1)o + (1+0.09)g = o + g + 126\) 

Plug the first equation into the second and simplify and solve for g

Then use that value to calculate o

Finally find o + g

Let the original number of grapes = x

Then the original number of oranges = 1.2x

10% increase in oranges = (1.1)(1.2)x

9% increase in number of grapes = (1/09)x

So.....when126 fruits were added

x + 1.2x + 126  =  (1.1)(1.2)x  + (1.09)x        simplify

2.2x + 126  =  1.32x + 1.09x

2.2x - 1.32x - 1.09 x  =  - 126

-.21x = -126   divide both sides by  -.21

x = 600  =   original number of grapes

1.2(600)  =  720  =  original number of oranges

For goodness sakes Chris, stop putting full answers after people have tried to teach something.

You are preventing children from learning and you are facilitating cheating!