Any number which is divisible by both 3 and 5 must….. A. be a factor of 15

B. be an odd number

C. end with a five

D. be a multiple of 15

D

Step-by-step explanation:

A is wrong because a factor of 15 is not divisible by both

B is wrong because 30 is even and divisible by both

C is wrong because 30 does not end with a 5

D is correct because there are no numbers other than multiples of 15 that doesn't lead to a decimal when you divide by those numbers

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.