Math Answers

Suppose f : N → N is a function defined by ƒ(x) = a(x + b), where a, b E N. If f is a bijective function,

then find the value of a + b.

(D ^ 2 + 3D + 2) * y = sin 2x + 5 degrees + log 3

Hannah made a bank loan worth Php 200,550 with 5% interest compounded semi-annually (2 times in a year). If she is to pay at the end of the period only, how much will be the value of the loan after 2 years?

Two tetrahedral die with faces labelled 1,2,3and 4are thrown and the number on which each leads in noted the score is the sum of these two number.find the probability that (a)the score is even in seat at least one die lands on a 3

(b)at least one die lands on a 3,given that the score is even

 It has been found from experience that the mean breaking strength of a brand of thread is 500 grams. With a S.D of 40gms. From the supplies, received during the last month, a sample of 16 pieces of thread was tested which showed a mean strength of 450 grams. Can we conclude that the thread supplied is inferior.

A vending treasury is purchased for RM 2,800 in cash with RM 700 down payment and fourteen monthly payments. If the interest calculated is 10% per annum, using the fixed rate equation calculation find:

I. Total interest charged

Secondly. monthly payment

prove a --> ( b V c ) using contradiction method and combination of inference rules and equivalence laws from these premises : 1. a --> ( d V b ) 2. d --> c

The raw data has been organised in the frequency table below.

games frequency

6 2

7 5

8 n

9 4

10 4

11 2

12 2

13 2

(a) Write down the value of n.

(b) Calculate the mean number of games played per set.

(c) What percentage of the sets had more than 10 games?

(d) What is the modal number of games?

The following table shows the income distribution of 600 families. Find the minimum income

of the riches 30% families. Also the limits of income of middle 50% of families, to the nearest

rupees.

Income Below

75

75-

150

150-

225

225-

300

300-

375

375-

400

400 &

above

No. of

families

69 137 225 46 88 25 10

Ans.: the richest 30 % families earns Rs. 222 and above per week , the middle 50% families

weekly income lies between 120 and 256.

The average time it takes a group of Senior High School student to complete a certain examination is 48.2 minutes. The standard deviation is 7 minutes. Assume that the variable is normally distributed. If 20 randomly selected SHS student take the examination, what is the probability that the mean time it takes the group to complete the test will be more than 45 minutes?