Then * * * Need 1 hour 40 minutes +24 hours +6 hours 50 minutes =3 1 hour 90 minutes =32.5 hours.

Because the average speed of this train is 80 kilometers per hour.

So the distance between Party A and Party B =80*32.5=2600km.

2) Let Koharu be x years old, then his mother is (x+27) years old and his grandfather is 2(x+x+27)=4x+54 years old.

Dad's age is 4x+54-38=4x+ 16 (years old).

And because Koharu's family of four is 147 years old this year.

So x+x+27+4x+54+4x+16 =147, that is, 10x=50 and x=5.

That is, when Koharu was 5 years old, his mother's age was (5+27)=32 years old, and his grandfather's age was 4*5+54=74 years old.

Dad's age is 4*5+ 16=36 (years old).

3) If there are 8s boys in Class 2, Grade 6, there will be 9s girls.

After switching to 1 girl, the number of boys is six-sevenths of that of girls, so 8s = 6/7 * (9s+ 1), and s = 3.

So there are 8*3=24 boys and 9*3=27 girls in Class Two, Grade Six.

4) A straight line can divide a plane into 2=( 1+ 1) regions, two straight lines can divide a plane into 4=2+2 regions at most, and three straight lines can divide a plane into 7=4+3 regions at most, so four straight lines can divide a plane into 7+4 =1at most.

That is, the area divided by n lines =n- 1 lines+number of lines n =1+1+2+3+4+5+...+n = (n+1) n/2+1.

So four straight lines can divide a plane into (10+1)10/2+1= 55+1= 56 regions at most.

5) Because a. No two people like the same kind of ball, that is, 1 people only like 1 balls.

B. Zhang Qiang doesn't like football, that is, Zhang Qiang likes basketball or table tennis.

C students who like basketball are younger than Li Hong, that is, Li Hong likes table tennis or football.

D. Zhang Qiang is one year older than his classmates who like table tennis, that is, Zhang Qiang likes football or basketball.

So B and D introduced that Zhang Qiang likes basketball, and C introduced that Zhang Qiang is younger than Li Hong.

Plus D, Li Hong doesn't like table tennis, and C, Li Hong likes football.

So Wang Ming likes table tennis.

6) Because the sum of any two sides of a triangle is greater than the third side, and 2+3 < 7.

So three lines of 2 cm, 3 cm and 7 cm cannot form a triangle.