The answer is 75.
Let's look at your problem shall we:
Odd number: It should end with the numbers 1,3,5,7, and 9.
The number is less than 100: It should be from the number 1-99
Sum of digits: 12
Multiple of 15: 15, 30, 45, 60, 75, and 90.
We can rule out 30, 60, and 90 because they are even.
1+5 = 6; 4+5=9; 7+5 = 12
You are left with 75.
ANSWER: 312 3/8
So Volume is Length • Width • Height
So first we would put it into this formula:
8.5 • 5.25 • 7= 312.375, or, 312 3/8
D:3, 5, 7, 9, 11
R: -2, 2, 6, 10, 14
If you're asking the height of the triangle, it is 2x-1.
I got the 2x from "twice the length of the base"
and (-1) from "1 cm less"