# problems on numbers

7. | The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Their sum is: | |||||||

Let the numbers be Then, (a + b + c) ( |

8. | A number consists of two digits. If the digits interchange places and the new number is added to the original number, then the resulting number will be divisible by: | |||||||

Let the ten’s digit be Then, number = 10 Number obtained by interchanging the digits = 10 (10 |

9. | In a two-digit, if it is known that its unit’s digit exceeds its ten’s digit by 2 and that the product of the given number and the sum of its digits is equal to 144, then the number is: | |||||||

Let the ten’s digit be Then, unit’s digit = Number = 10 Sum of digits = (11 22 11 ( Hence, required number = 11 |

10. | Find a positive number which when increased by 17 is equal to 60 times the reciprocal of the number. | ||||||||||

Let the number be
( |