It takes 40 minutes for a to walk a part of the way and 30 minutes for B to walk a part of the way. Starting from the same place, a walks for 5 minutes first, B starts to chase, and B starts to chase___ It's only ten minutes to catch up with a

It takes 40 minutes for a to walk a part of the way and 30 minutes for B to walk a part of the way. Starting from the same place, a walks for 5 minutes first, B starts to chase, and B starts to chase___ It's only ten minutes to catch up with a

So B can catch up with a in 15 minutes

It takes 30 minutes for a to walk and 40 minutes for B. If a starts from the same place, B will walk for 10 minutes first, and a will start to catch up. How many minutes can a catch up with B?

In fact, this question is nothing, from the conditions can see that it is 30 minutes
I'd better solve it
Let the velocity of a be x and the velocity of B be y, then 30x = 40y and x = 4 / 3Y
Let a catch up with B after Z minutes, then ZX = 10Y + ZY
If we take X in, 4Z / 3Y = 10Y + ZY, 4Z / 3 = 10 + Z
z=30

How long does it take for a to catch up with B when a walks for 30 minutes, B for 40 minutes, B for five minutes first

A: 1 / 30 = 1 / 30
B: 1 / 40 = 1 / 40 for each branch
B 5 branch: 1 / 40 × 5 = 1 / 8
1 / 8 (1 / 30-1 / 40) = 15 (minutes)

A goes first 40 points, B uses 30 points to pursue, then a goes first 30 points, then B uses how many points to pursue?