A clay layer in field is 3-m thick and is sandwiched between twosand layers (drained from top and bottom). The saturated stratum ofclay is under a surcharge loading and underwent 90% primaryconsolidation in 75 days. The time required in minutes for a 30 mmthick undisturbed clay sample obtained from the field to undergo90% consolidation in laboratory is most nearly equal to
Select one:
a. 28
b. 67.5
c. 100
d. 10
