At present operating income is 1.3 times of present interest expense (10*1.3 = 13 crore), now in coming year it would decrease by 10% as per question hence it would become 11.7 crore(13*.90 = 11.7).
Now how much more interest can the company bear can be worked out
which is ==>> 11.7 - 10 = 1.7crore.

now to pay up to 1.7 crore we can take this much loan@10%
1.7/10 * 100 = 17 crore.