Homework Answers

A tradesman marks his goods 25% above the cost price and allows his customers 12% reduction on their bills. What percent profit does he make?

Let R1 and R2 be two relation on real number such that R1 = {(x, y)|x < y} and R2 =

{(x, y)|x > y}, then find R1 ∪ R2,R1 ∩ R2,R1 − R2, R2 − R1, and R1+LR2.

There are 150 students in a class. The distribution if their marks in a mathematics test are as follows

Class                                                   frequency

0-9                                                      3

10-19                                                  10

20-29                                                  17

30-39                                                  x

40-49                                                  35

50-59                                                  y

60-69                                                  18

70-79                                                  10

80-89                                                  5

90-99                                                  2

Required

i)       The value of x given that the median mark is 44.357            (2marks)

ii)     The value of y given that the modal is 43.0                          (2marks)

iii)   Draw an ogive of the data in (a) above                                  (3 marks)

A real estate agent sells two sites for P18,000 each. On one he gains 25% and on the other he loses 25%. What is his loss or gain percent?

Suppose that the average outstanding credit card balance for young professionals

is Php11,200 with standard deviation of Php 2,600. In simple random sample of

150 young professionals, what is the probability that the mean outstanding credit

card balance does not exceeds Php12,300?