$8$

$0$

$\%$

$$Estimate

$($

days

$)$

$$Max$.$ duration

$($

days

$)$

$$A

$1$

$7$

$2$

$2$

$$D

$1$

$4$

$1$

$5$

$$E

$7$

$1$

$0$

$$F

$9$

$1$

$1$

$$H

$1$

$4$

$1$

$8$

$$

$$For the above data for critical path with the precedence A

$-$

D

$-$

E

$-$

F

$-$

H

$,$

$$the recommended project duration for

$9$

$0$

$\%$

$$confidence level using USM is

$?$

$$How many days?