I believe 30 is the answer :)
7 is 1/10 of.. 70, because 10 times 7 is 70 :)
Answer:

Step-by-step explanation:
It is given that triangle AOC intersects a circle with center O, side AO is 10 inches and the diameter of the circle is 12 inches, thus
OC is the radius of the circle and is equal to
.
Now, From ΔAOC, using the Pythagoras theorem, we get

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start with 396 , then subtract 60