The correct answer is - in the place of the ten thousands.
If the first number 7 is placed in the place of the tenths, than it means that its value is ten times greater then the number itself, so it will have a value of 70, as 7 x 10 = 70.
On the other hand we have another number 7, that should be 1,000 times greater than the number seven in the tenths, or rather the number 70. In order to get to the answer we just need to multiple the number 70 with 1,000:
70 x 1,000 = 70,000
This means that the second number 7 is on the place of the ten thousands.