Given
The sum of three numbers is 78.
The second number is twice the first.
The third number is 3 times the first.
Step-by-step explanation
Let the first number be x, second number be y and third number be z.
From the given condition , equations formed are
Substitute the values from the equation 2 and 3 in equation 1.
Then the first number is 13 and second and third number is determined by substitute the value of x in equation 2 and 3,
AnswerHence the first number is 13, second number is 26 and third number is 39.