in a class of 80 students in Debre Berhan university,45 good in mathematics,15 are good in both Mathematics and English,13 are good in both Mathematics and Psychology, 16 are good in both in English and psychology,20 are good in Psychology and 9 are good in both of the three courses A, how many students are good in mathematics only? B, how many students are not good in any of three courses?

60: 45 =12: 9 =4: 3 so the answer is 4: 3

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64

answer is (b.

164 ft2)

a base  

18

b base  

7

h height  

8

answer: the proof is mentioned below.

step-by-step explanation:

since, given:   lines bc = ef

prove:   lines ac > ef

          statements                                           reason

1. bc=ef                                           1. given

2. ac= ab+bc                                 2. because b is the point between the  

                                                            line segment ac

3.   ac > bc                                       3. because if a line segment is equal to

                                                          the sum of two line segments then it is

                                                          always greater then each of these

                                                          individual line segments

4. ac > ef                                         4. by equality property.