In a row of forty children, K is thirteenth from the left end and B is ninth from the right end. How many children are there between K and M if M is fourth to the left of B?

14

In a row of forty children, K is thirteenth from the left end and B is ninth from the right end.

M is fourth to the left of B.

Therefore, the position of M from the right end = 9 + 4 = 13th

Number of children between K and M = 40 - (13 + 13)

= 40 – 26 = 14