1, there are 52 weeks in a year and 52× 3 = 156 days in three years.

2、2^64- 1= 1844674407370955 16 15

There are x in the gold box and y in the silver box.

3/4x-5=x/4+5+ 10

(4/5y-4)/(y/5+4)=2/ 1

Solution: x=40, y=30.

So there are forty or thirty jewels in the gold box and the silver box.

4. Because the third person was given the last half and three, and then there were no plums in the basket, the third person got six plums.

Suppose there is X before the second person, then

X/2- 1=6, so x= 14.

There are many plums in the basket, so

Y/2- 1= 14, so y=30.