Apparently this is a really simple problem but I can't seem to figure it out. It's a data sufficiency problem:
Is x + y < 1?
a) x < 8/9
b) y < 1/8
The answer is E (both aren't sufficient) but can someone explain why it's not C (both taken together are sufficient)?
Max of x = 8/9
Max 0f y= 1/8
Max x + Max y = 8/9+1/8 = 73/72 = 1 1/72
x+y can be 1 0.00000000001/72 so x+y>1
other case x+y can be less than 1
Techinically Max value of X cannot be 8/9 and Y cannot be 1/8. They are < and not <=
You can instead write equality like
x < 8/9 and Y < 1/9
so x + y < 1+1/72
Answer is still E though