the answer given is A i.e. X is greater however if we put X as 4 it would still round off to 12.16 right?

in manhattan they have considered that we can roundoff to higher digit if the no. is greater than or equal to 5.

so , to make it 12.16 ; x should be >=5. is right

The question asks about rounding the number to the nearest hundredth. It is math convention that 5, 6, 7, 8, 9 round up while digits 0, 1, 2, 3, 4 leave the number unchanged. Thus, in this example since 12.15x9 rounded to the nearest hundredth gives you 12.16, then x must be 5 or 6 or 7 or 8 or 9.

but wouldn’t the 9 play a part?

For example, if X = 4 then 9 would change X i.e. 4 to 5. Therefore rounding off the hundredth place would still lead to 12.16 with X >= 4?

Yep had the concept wrong. Thanks!

can’t 12.1549 be rounded to 12.16?

No. Check out the videos above to review the concept.