Answer:
[tex]3\ \frac{15}{16}[/tex]
Step-by-step explanation:
The mixture requires 3/8 cup of plant food for every gallon of water
Then it requires (10 1/2)×(3/8) cup of plant food for 10 1/2 gallons of water
Now we have to calculate (10 1/2)×(3/8)
[tex]10\ \frac{1}{2} \ =\ \frac{10\times 2}{2} +\frac{1}{2} \ =\frac{20+1}{2} =\frac{21}{2}[/tex]
[tex]\frac{21}{2} \times \frac{3}{8} =\frac{63}{16} =3\ \frac{15}{16}[/tex]
then he needs :
[tex]\frac{63}{16}\ \ \text (cup\ of\ plant\ food)[/tex]
