A number

, where

are distinct prime numbers, has

divisors.
We know that

has 7 divisors. 7 is a prime number, so among the numbers

there is only one that is equal to 7.
So,

That means

where

is a prime number.

, therefore the

has

divisors.
Answer:
first, second and fourth are all correct
Step-by-step explanation:
Answer:
c+d>15
Step-by-step explanation:
Usually there's more to the question.. the inequality doesn't look too right, but it could be.
Answer:
280.5 mm^2
Step-by-step explanation:
scale * 25.5 mm = 127.5 mm 1275/25.5 = 5 scale factor
25.5 * 55/5 = 280.5 mm^2
Check the picture below, it hits the ground when y = 0.