Questions is asking about what is the smallest power of 10 that would exceed 234,567,890.
To find that first we need to check how the powers of 10 changes the size of number. So let's find poers of 10 as shown below:
On this pattern we see that as the exponent increases by 1 then a zero increases in the output.
In given number 234567890, there are 9 digits. So we need at least 9 zeroes which is
1000000000 or
Clearly 1000000000 exceeds 234567890.
Hence the final answer is that exponent of 10 will be 9.