(a) The total value of a two digit number is 10x + y
(b) Let the number be xy
3(x + y) =(10 + y) + 8
3x + 3y = 10x + y + 8
7x - 2y = 8
The reversed number is yx
Therefore 10y + x - 10x - y = 9
9y -9x = 9
9(7x -2y = 8)
2(-9x + 9y= 9)
63x - 18y = 72
-18x + 18y = 18
45x = 90
x = 2
7x - 2y = 8
14 - 2y = 8
2y = 6
y = 3
The number is 23
raphael answered the question on January 24, 2017 at 05:13
-
Three ladies Agnes, Betty and Cate contributed a total amount of sh 21,000 to start a saloon. The ratio of Agnes to Betty was 3:5 and that of Betty to Cate was 2:1.
(Solved)
Three ladies Agnes, Betty and Cate contributed a total amount of sh 21,000 to start a saloon. The ratio of Agnes to Betty was 3:5 and that of Betty to Cate was 2:1. How much did Betty contribute?
Date posted:
January 24, 2017
.
Answers (1)
-
Simplify the equation $\frac{(wx - xy - wz + yz)(w + z)}{z^2 - w^2}$
(Solved)
Simplify the equation $\frac{(wx - xy - wz + yz)(w + z)}{z^2 - w^2}$
Date posted:
January 23, 2017
.
Answers (1)
-
The angle of elevation of the highest point of a building from two points S and T are 60o and 30o
(Solved)
The angle of elevation of the highest point of a building from two points S and T are 60o and 30o.T is vertically above S and ST = 10 m. Calculate the height of the building above the level S.
Date posted:
January 20, 2017
.
Answers (1)
-
ABCD is a rhombus whose diagonals BD and AC intersect at O. If BD = 10 cm and AC = 6 cm
(Solved)
ABCD is a rhombus whose diagonals BD and AC intersect at O. If BD = 10 cm and AC = 6 cm, find the angles of the rhombus.
Date posted:
January 20, 2017
.
Answers (1)
-
Simplify $\frac{2a^2 - 3ab - 2b^2}{4a^2 - b^2}$
(Solved)
Simplify $\frac{2a^2 - 3ab - 2b^2}{4a^2 - b^2}$
Date posted:
January 20, 2017
.
Answers (1)
-
Given that $6.5\le x \le 10$ and $2.5 \le y \le 4$ find:
(Solved)
Given that $6.5\le x \le 10$ and $2.5 \le y \le 4$ find:
(a) The maximum value of $\frac{x}{y}$
(b) The minimum value of x + y
Date posted:
January 17, 2017
.
Answers (1)
-
The length of a rectangle is increased by 10% and the width by 20%. What is the percentage change in area?
(Solved)
The length of a rectangle is increased by 10% and the width by 20%. Determine the percentage change in area.
Date posted:
January 17, 2017
.
Answers (1)
-
The following data shows sizes of shoes worn by eleven form two students.
(Solved)
The following data shows sizes of shoes worn by eleven form two students.
6, 7, 7, 4, 8, 10, 9, 7, 5, 6, 5. Determine the interquartile range of the shoe sizes.
Date posted:
January 17, 2017
.
Answers (1)
-
Given that log 7 = 0.84510, log 5 = 0.69897 and log 2 = 0.30102, find
(Solved)
Given that log 7 = 0.84510 and log 5 = 0.69897, find the logarithm of 980 without using tables or calculator
Date posted:
January 16, 2017
.
Answers (1)
-
Calculate the equation of a mirror line that reflects A(2, 7) onto A' (6, -1)
(Solved)
Calculate the equation of a mirror line that reflects A(2, 7) onto A' (6, -1)
Date posted:
January 16, 2017
.
Answers (1)
-
Make x the subject of in the following expression
(Solved)
$\frac{x^4 - 4}{x^2 -2} \ = K$
Date posted:
January 16, 2017
.
Answers (1)
-
The difference between two digits is 8. Find the value of the two digits if their product is to be maximum
(Solved)
The difference between two digits is 8. Find the value of the two digits if their product is to be maximum
Date posted:
January 16, 2017
.
Answers (1)
-
Find the percentage change from question given below
(Solved)
If $ 2^{x + 5} = (\frac{1}{16})^{-1}$ and 42x - y =$\frac{1}{4}$ increase 105 in the ratio $y - x:\frac{1}{3}y$ and find the percentage change.
Date posted:
January 16, 2017
.
Answers (1)
-
20 soldiers left for war and carried food that would last 7 days
(Solved)
20 soldiers left for war and took with them food that would last 7 days. After 4 days, 4 of the soldiers were recalled back to the headquarters. For how long did the remaining food last if the rate of consumption remained unchanged?
Date posted:
January 16, 2017
.
Answers (1)
-
Determine the change in the family's monthly expenditure on vegetables from the information given below
(Solved)
John's family spends Ksh. 2,700 per month on vegetables. Last month, the price of vegetables went up in the ratio $1\frac{1}{4}$:1. If the family decided to reduce the amount of vegetables consumed in the ratio $\frac{14}{15}$, determine the change in the family's monthly expenditure on vegetables.
Date posted:
January 16, 2017
.
Answers (1)
-
The perimeter of a rectangle is $4(2 + \sqrt{3}) \ cm$. One of its sides is $1 + \sqrt{3}$ cm long. Find the area of the rectangle.
(Solved)
Find the area of the rectangle if the perimeter of a rectangle is $4(2 + \sqrt{3}) \ cm$ and one of its sides is $1 + \sqrt{3}$ cm long.
Date posted:
January 16, 2017
.
Answers (1)
-
Without using mathematical tables or a calculator, find the exact value of
(Solved)
$\frac{28 \times 5.54 + 72 \times 5.54}{7.77^2 - 2.23^2}$
Date posted:
January 16, 2017
.
Answers (1)
-
Find the number of sides of the polygon
(Solved)
A polygon has (n - 1) sides. Two of its angles are right angles and each of the remaining angles is 144o. Find the number of sides of the polygon.
Date posted:
January 16, 2017
.
Answers (1)
-
Solve for x in the equation below
(Solved)
sin 3x - cos 3x = 0 for 0o$\le x \le $360o
Date posted:
January 16, 2017
.
Answers (1)
-
List the integers that satisfy the two inequalities below
(Solved)
$\frac{x}{2} - 1 \lt \frac{x}{5}, \frac{3}{8} + \frac{x}{3} \ge \frac{x}{4}$
Date posted:
January 16, 2017
.
Answers (1)