The difference between a number and its three-fifths is 150. What is the number?

Question: The difference between a number and its three-fifths is 150. What is the number?

Solution:
Let the number be x
Three-fifths of x is 3x/5

According to the question:
x - (3x/5) = 150
⇒ (5x - 3x)/5 = 150
⇒ 2x/5 = 150
⇒ 2x = 150 × 5
⇒ x = (150 × 5)/2
∴ x = 375