Estimate complete calculation

 Greetings,

came across this question and wanted to know the correct method of calcuation to get the answer - not sure of answer though - sorry

Project exploration - team has to reach XYZ. 

TASK                                                    DURATION

Transportation to xyz                             20days

food and equiment                                5days

staff                                                     10days

task1                                                    5days

travelling 200km at 10km/day speed       20days

task2                                                    0days

 the constraint is task1 , food & equiment, staff  has to start at same time

halfway through the project due to storm the speed is reduced by 25%

 

how many days will team take to reach XYZ.

Appreciate your response. 

Longest path is the project duration. So, even 3 tasks reduced by 25%, the longest duration would be 20days. 

In normal case distrace travelled is 10KM/day, due to strom constraints now their speed is 7.5KM/Day.

Hence to cover 200 KM they will be required 26.66 Days

 

Regards,

Manoj

 @Manoj - it says halfway through the speed resduced  hence can we assume its to cover another 100km with speed of 7.5km/day it takes 13 days??

 May I know the source please?

 this was a pmp actual exam question