Question

Mohsin is thinking of two numbers. The first number is smaller than the second number. The sum of the two numbers is 72 and their difference is 18. What is the ratio of first number to the sum of the two numbers

Answer 1

Answer:

Let the small unknown number = x

X + 3X = 72

4X = 72

X=72/4 = 18

The small number is = 18.

The larger number can be solved by how we defined it earlier.

Let the bigger number = Y.

Y=big number

Remember it's also equal to 3 times the small number.

3X=Y

We substitute the known value of X

3 * 18 = Y = 54

Answer 2

Answer:

Given that ;

Mohsin is thinking of 2 numbers

First number is smaller than Second Number

Let

The first number be x

The second number be y

• x < y

Sum of the numbers = 72

• x + y = 72 ------ ( 1 )

Difference of the numbers = 18

• x - y = 18 -------- ( 2 )

Compare both the Equations ;

x + y = 72

x - y = 18

+

------------

2x = 90

-------------

2x = 90

x = 90 / 2

x = 45

Substitute x value in the Equation ( 1 ) :

x + y = 72

45 + y = 72

y = 72 - 45

y = 27

x < y ( According to the given information )

Hence ;

x = 27

y = 45

Proof :

Substitute x , y values in Equation ( 2 ) ;

x = 27 ; y = 45

x - y = 18

45 - 27

18

Ratio of first number to the sum of two numbers ;

First Number ( x ) = 27

Sum of two numbers ( x + y ) = 27 + 45

= 72

Ratio :

27 : 72

3 : 8