What are the numbers?

Question

The sum of three numbers is 75. The second number is 5 more than the first , and the third is three times the second. What are the numbers?

Answer 1

Hi Jodi,

If you know the total of the numbers is 75, you can write an equation equal to 75.

 

The first number is X;

The second number is X + 5; and

the third number is 3(X + 5).

So your equation is:

75 = X + (X + 5) + 3(X + 5)

You can figure out this equation by just reading the problem carefully and adding the three numbers. Now you have to figure out what X is to find out what the three numbers are:

75 = X + (X + 5) + 3(X + 5)

75 = 2X + 5 + 3X + 15

75 = 5X + 20 75 - 20 = 5X 55/5 = X X = 11

The second number is 11 + 5 or 16 and

the third number is: 3(X + 5) = 3(11 +5) = 3(16) = 48

 

The answer is 11, 16, and 48.

 

If any of this doesn't make sense to you, please give me a call at [phone].

 

Tom D.

Answer 2

x, y, and z are the numbers

x+y+z=75

x=first

y=second

z=third

x=first

x+5=second

3(x+5)=third

x+(x+5)+3(x+5)=75

x+x+5+3x+15=75

5x+20=75

5x=75-20

5x=55

x=55/5

x=11

x+5=16

3*16=48

11, 16, and 48 are the numbers