Respuesta :
The first number is 15. The 2nd number is 30 cuz it’s double the first. The third number is 18 less than 30 so it is 12. They all add up to 57. Third # = 12
Answer:
12
Step-by-step explanation:
Suppose,
The first number is = x
so, the second number is = 2x
so, the third number is = 2x-18
Questionwise,
x+2x+2x-18 = 57
5x = 75
x = 15
so, the third number = (2×15)-18 = 12