Question

The sum of one-eight, one-twelfth and one-twentieth parts is 31, find the number.

Answer 1

Let the no. be x...

Then,

x/8 + x/12 + x/20 = 31

So,

(15x + 10x + 6x)/120 = 31

So,

31x/120 = 31

Hence,

x = 31 * 120/31

= 12

Answer 2

Answer:

120

Step-by-step explanation :

Let the number be X,then

1/8 X + 1/12 X + 1/20 = 31

LCM of 8,12,20 is 120 so we get,

(15 X + 10 X + 6 X )/120 = 31

31 X/120 = 31

X = 12