#### Answer

1 $\frac{31}{48}$ ton

#### Work Step by Step

Let the cooling requirements of the three seperate incubation rooms are $\frac{1}{3}$ ton , $\frac{3}{4}$ ton and $\frac{9}{16}$ ton
therefore total tons required to install central HVAC unit = $\frac{1}{3}$ ton + $\frac{3}{4}$ ton + $\frac{9}{16}$ ton
= $ \frac{1}{3} \times$ $\frac{16}{16}$ + $ \frac{3}{4} \times$ $\frac{12}{12}$ + $ \frac{9}{16} \times$ $\frac{3}{3}$
=$\frac{16}{48}$ ton + $\frac{36}{48}$ ton + $\frac{27}{48}$ ton
= $\frac{79}{48}$ ton
=1 $\frac{31}{48}$ ton