103k views
3 votes
Three-sevenths of a number is 21. Find the number

1 Answer

4 votes
Let x = the unknown number.
Because three-sevenths of the number is 21, therefore
(3/7)x = 21

That is
(3x)/7 = 21

Multiply each side by 7.
3x = 21*7 = 147

Divide each side by 3.
x = 147/3 = 49

Answer: 49
User Abudis
by
8.1k points