Item 21
You know that 15% of a number n is 12. How can you use this to find 30% of n? 45% of n? Explain.

Because 30% of n is equal to
times 15% of n and 45% of n is equal to
times 15% of n, you can write

30% of n=
×12=

and

45% of n=
×12=
.