triangle inequality and expected value 的數唔識

How many different triangles can be constructed so that the lengths of the three sides are x cm, 2x cm and 12 cm, where x is and interger.

x+2x > 12
x>4
2x+12>x
x>-6
12+x>2x
12>x

x>4, x>-6, x<12

x<12
it can be 11, 10, 9, 8, 7, 6, 5
but x > 4

so it can be 11, 10, 9, 8, 7, 6, 5