40% of ? = 18: Percentage of 40 (Percent) Calculated of What Unknown Number Equals the Given Value, 18? How To Find the Missing Number? Online Calculator. Steps, Explained

40% of what missing number = 18?

Number calculation, finding the missing unknown number
(Percentage of) 40% of what number = 18?

A percentage value is nothing but a fraction with a denominator of 100:

40% = 40/100 = 40 ÷ 100 = 0.4

Let N be the number that we have to calculate:

To calculate a percentage of 40% of the number N is equivalent to multiplying them: 40% × N


40% of N = 18 ⇔

40% × N = 18 ⇒

N =

18 ÷ 40% =

18 ÷ (40 ÷ 100) =

18 × (100 ÷ 40) =

(100 × 18) ÷ 40 =

1,800 ÷ 40 =

45

(Percentage of) 40% of what number = 18?
40% of 45 = 18

The symbols used: % percent, ÷ division, × multiplication, = the equal sign, / the fraction bar, ≈ approximately the same. Writing numbers: comma ',' - as a thousands separator, point '.' as a decimal mark.


Other similar operations, calculating the missing number:

» 40% of what missing (unknown) number is equal to 23.2?



Percentage of what number equals the other given value?

Calculated percentage of which number is equal to the given value?

  • p% of what missing number = the given number N?

Three examples of problems that can be solved out using the information in this section:

  • Problem 1:

  • 25% of the annual profit of a company was invested in buying some new equipment. The total amount invested in buying the new equipment was 100,000 dollars. What was the annual profit of the company?
  • Rewrite: 25% of the Profit means 100,000 dollars => 25% × Profit = 100,000 dollars => Profit = 100,000 ÷ 25% dollars = 100,000 ÷ 25/100 dollars = 100,000 × 100/25 dollars = 100,000 × 4 dollars = 400,000 dollars;

  • Problem 2:

  • A number of 20% of the students in the terminal year have enrolled into the swimming class. In total, 7 students have enrolled. How many students are in the terminal year?
  • Rewrite: 20% of the students means 7 students => 20% × Total number of students = 7 => The total number of students = 7 ÷ 20% = 7 ÷ 20/100 = 7 × 100/20 = 7 × 5 = 35;

  • Problem 3:

  • In the last elections 49% of community memebrs voted for the A Party, 32% for the B Party, and the rest for the C Party. 17,920 people voted for the B Party. How many members are in the community, all in all?
  • Rewrite: 32% of the total community members means 17,920 people => 32% × The total number of community members = 17,920 => The total number of community members = 17,920 ÷ 32% people = 17,920 ÷ 32/100 people = 17,920 × 100/32 people = 17,920/32 × 100 = 560 × 100 people = 56,000 people.