Correct Answers: | |

Wrong Answers: | |

Unattempted: |

### Question 1

When a two digit number is reversed and added to itself we get 110. The product of the digits of that number is 21. What is the number?

**A**

73.

**B**

74.

**C**

72.

**D**

75.

**Soln.**

**Ans: a**

Let the number be ab. When it is reversed and added to itself we get (10a + b) + (10b + a) = 11 × (a + b). We are given 110 = 11 × (a + b) ⇒ $a + b = 110 / 11 = 10$, so the digits are $a$ and $10 - a$. We are given their product as a × (10 - a) = 21, which is a quadratic expression that can be simplified to $(a - 7) × (3 - a) = 0$. So the number could be 73 or 37.

### Question 2

The sum of two numbers is 25. Their difference is 19. They are in the ratio?

**A**

$7{1/3}$.

**B**

$12{1/2}$.

**C**

$6{1/3}$.

**D**

$6{1/5}$.

**Soln.**

**Ans: a**

Let the numbers be a and b, and let their ratio be k such that $a/b = k$. We are given $a + b = 25$ ⇒ $b(k + 1) = 25$. Similarly, from the difference we can obtain $b(k - 1) = 19$. Dividing we get ${k + 1}/{k - 1} = 25/19$. By componendo and dividendo, $k = {25 + 19}/{25 - 19}$ = ${22/3}$, which is same as: $7{1/3}$.

### Question 3

If ${23/34}$ of a number is 17, what is ${19/21}$ of that number?

### Question 4

The sum of two numbers is 24. Their product is 143. One of the two numbers is?

### Question 5

The sum of three consecutive integer numbers is -1113. The smallest of the three is?

### More Chapters | See All...

Problems on Numbers | abba Series | Passwords and Inputs | Problems on Ages | Boats and Streams | Square and Cube Roots | Ranking Test | Simple Interest | Surds and Indices | Venn Diagrams | More...

This Blog Post/Article "Problems on Numbers Quiz Set 009" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Updated on 2019-08-18.