25
The triangle given by 9, unknown, and 15 and the triangle given by 15, unknown, and x are similar triangles and therefore 9:15 = 15:x
X is 25 in this case
the answer is B) 19 × 11 = 209
coz A prime number is a whole number greater than 1 whose only factors are 1 and itself.
but here it is a multiple of 11 and 19 ....
so its proved
I think the answer is 8.5 h
