math

posted by .

How many strings of length 13 can be formed from 9 1's, two ('s and two )'s such that the substring () never occurs, and for k=1,2, we see k('s before k)'s?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A ball of mass m = 500g moves around a vertical axis with an angular speed ù. It is attached to two strings of length: the upper a = 30 cm and the lower b = 40 cm.Both strings are taut and perpendicular to each other. Each of the …
  2. Physics

    Please someone help me I'm desperate!!!! Two steel guitar strings have the same length. String A has a diameter of 0.59 mm and is under 420.0 N of tension. String B has a diameter of 1.3 mm and is under a tension of 840.0N . Find the …
  3. Physics

    Standing waves are set up on two strings fixed at each end, as shown in the drawing. The two strings have the same tension and mass per unit length, but they differ in length by 0.55 cm. The waves on the shorter string propagate with …
  4. physics

    Two balls have the same mass of 3.085 kg and identical charges of 21.0 ìC. They hang from the ceiling on strings of identical length as shown in the figure. If the angle with respect to the vertical of the strings is 22.0°, what …
  5. physics

    Two balls have the same mass of 0.525 kg and identical charges of 13.0 μC. They hang from the ceiling on strings of identical length as shown in the figure. If the angle with respect to the vertical of the strings is 22.0°, what …
  6. physics

    a 1.29 kg ball is connected by means of two massless strings to a vertical, rotating rod. The strings are tied to the rod and are taut. The tension in the upper string is 38 N. The length of both strings is 1.70m and the distance between …
  7. Physics

    4 kg mass is placed on the smooth horizontal tabke.two light inextansible strings are connected to it and two masse 2kg and 5kg are attached to the free ends of the strings. Find the accelaration of each objects and the tension of …
  8. physics

    Two strings are vibrating at the same frequency of 113 Hz. After the tension in one of the strings is decreased, an observer hears two beats each second when the strings vibrate together. Find the new frequency in the adjusted string.
  9. Elective maths

    A particle P of mass 7kg is suspended by two inextensible strings AP,BP of lengths 40cm and 75cm respectively. The ends, AP of the strings are attached to two point at the same level, whose distance apart is 85cm. Find angle APB and …
  10. Physics

    A lamp of mass 5kg is hung from two hooks 2.5cm apart on the horizontal ceiling of room by strings of length 1.5m and 2m.Find tension in the strings?

More Similar Questions