Question

LCM of two number is 280 and their ratio is 7:8. The sum of the two numbers is

Answer 1

Answer:

The sum of the two numbers is 85.

Step-by-step explanation:

Given : LCM of two number is 280 and their ratio is 7:8.

To find : The sum of the two numbers ?

Solution :

Let the ratio be 'x'.

Let the two numbers are 7x and 8x.

The HCF of the two number is x as the common factor is x.

The LCM of two number is 280.

We know, $\text{Product of two number}=HCF\times LCM$

$7x\times 8x=x\times 280$

$56x^2=280x$

$x=\frac{280}{56}$

$x=5$

So, The required numbers are

$7x=7\times 5=35\\8x=8\times 5=40$

So, The sum of two numbers is 35+40=85

Therefore, The sum of the two numbers is 85.

Answer 2

Answer:

The sum of two numbers is 75.

Explanation

The ratio of two numbers are 7 : 8

Let the numbers be 7 x and 8 x

Their L. C. M is $7 \times 8 \times x=56 x$

Given L. C. M = 280

56 x = 280

x = 280/56

x = 5

The numbers are $7 x=7 \times 5=35,8 x=8 \times 5=40$

35 and 40 are the numbers

The sum of the numbers = 35 + 40 = 75