Answer:
2.3
Step-by-step explanation:
Answer:
12: 138
13: 35
14: 49
Step-by-step explanation:
12: 180-42=138
13: 360-297-28=35
13: 90-41=49
Answer:

Step-by-step explanation:
GIVEN: two two-letter passwords can be formed from the letters A, B, C, D, E, F, G and H.
TO FIND: How many different two two-letter passwords can be formed if no repetition of letters is allowed.
SOLUTION:
Total number of different letters 
for two two-letter passwords
different are required.
Number of ways of selecting
different letters from
letters


Hence there are
different two-letter passwords can be formed using
letters.
We can see from the diagram that the length of the rectangle is 2 lots of the radius of one quarter circle. The width is made up of one radius, therefore the width is half of the length.
This means that the width of the rectangle is 9cm, and the radius of each quarter circle is 9cm.
To find the shaded area, we find the area of the rectangle and subtract from the areas of each circle, which are equal:
A = lw - 1/2(pi x r^2)
A = 9 x 18 - 1/2(81pi)
A = 162 - 81/2 pi
A = 34.8cm (3sf)