How many permutations exist of the letters pqrs and t taking four at a time

 120

Step-by-step explanation:

The given letters : P Q  R S T

Number of letters : 5

The formula of number of permutations of n things taken r at a time is given by :-

Similarly, the number of permutations of 5 letters taken four at a time is given by :-

Hence, there are 120 permutations exists of the letters PQRS and T taking four at a time.

d 25 pi/6

step-by-step explanation:

the diameter is 10 inches

the radius is 1/2 of the diameter or 5 inches

the area of the circle is

a = pi r^2

  = pi 5^2

  = 25 pi

the slice is 60 degrees of the entire circle.

60 degrees out of 360   60/360 = 1/6

the area of the slice is 1/6 of the circle

a slice = 1/6 a circle

a slice = 1/6 * 25 pi