Answer:
P = 0.25
Step-by-step explanation:
[tex]\frac{3}{5} (1+P) = \frac{21}{20}\\1+P = \frac{21(5)}{20(3)} \ \ \ times\ by\ 5\ and\ divide\ by\ 3\ in\ both\ sides\\P + 1 = \frac{7}{4} \\P + 1 = 1.25\\P = 1.25 - 1\ \ \ subtract\ 1\ from\ both\ sides\\P = 0.25[/tex]
