If one-third of one-fourth of a number is 15, then three-tenths of that number is?

Let, the number be x.

Given, one-third of one-fourth of the number is 15.

Or, (1/3)(1/4)x = 15

So, x = 15*3*4 = 180.

Now, three-tenths of that number will be ,(3/10)x = (3/10)*180 = 18*3 = 54.