Question

4. What is the number when 20% of number is 30%of 10
(a)90
(b)80
(c)60
(d)50​

Answer 1

Answer:

Step-by-step explanation:

Every statement of percent involves three numbers. For example,

8 is 50% of 16.

8 is called the Amount. 50% is the Percent. 16 is called the Base. The Base always follows "of." What you see above is the standard form of any statement of percent.

The Amount is some Percent of the Base.

In a percent problem, we are given two of those numbers and we are asked to find the third. We have already seen how to solve any percent problem with a calculator. The same procedures apply in a written calculation, in which we would typically change the percent to a decimal.

In Lesson 4 we saw how to take 1% and 10% of a number simply by placing the decimal point. Those should be basic skills. What is more, from 1% we can calculate 2%, 3%, and so on. While from 10% we can easily calculate 20%, 30% and any multiple of 10%.

In Lesson 28 we saw how to solve percent problems by understanding that a percent is a ratio. Here, we will continue those problems -- we will see how to find the Amount with a minimum amount of writing. And in Section 3 we will see how to find the Base.