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प्रश्न
Reena is 6 years older than her brother Ajay. If the sum of their ages is 28 years, what are their present ages?
उत्तर
Let the present age of Ajay be x years.
Since Reena is 6 years older than Ajay, the present age of Reena will be (x + 6) years.
According to the question:
x + (x + 6) = 28
or, 2x + 6 = 28
or, 2x + 6 − 6 = 28 − 6 [Subtracting 6 from both the sides]
or, 2x = 22
or, `(2x)/2=22/2` [Dividing both the sides by 2]
or, x = 11
∴ Present age of Ajay = 11 years
Present age of Reena = x + 6 = 11 + 6
= 17 years
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संबंधित प्रश्न
Observe the patterns of digits made from line segments of equal length. You will find such segmented digits on the display of electronic watches or calculators.
If the number of digits formed is taken to be n, the number of segments required to form n digits is given by the algebraic expression appearing on the right of each pattern.
How many segments are required to form 5, 10, 100 digits of the kind −
Use the given algebraic expression to complete the table of number patterns.
| S. No |
Expression |
Terms | |||||||||
| 1st | 2nd | 3rd | 4th | 5th | ... | 10th | ... | 100th | ... | ||
| 1 | 2n - 1 | 1 | 3 | 5 | 7 | 9 | - | 19 | - | - | - |
| 2 | 3n + 2 | 5 | 8 | 11 | 14 | - | - | - | - | - | - |
| 3 | 4n + 1 | 5 | 9 | 13 | 17 | - | - | - | - | - | - |
| 4 | 7n + 20 | 27 | 34 | 41 | 48 | - | - | - | - | - | - |
| 5 | n2 + 1 | 2 | 5 | 10 | 17 | - | - | - | - | 10001 | - |
The sum of three consecutive natural numbers is 114. Find the numbers.
A man is thrice as old as his son. Five years ago the man was four times as old as his son. Find their present ages.
The side of a regular hexagon is denoted by l. Express the perimeter of the hexagon using l.
(Hint: A regular hexagon has all its six sides equal in length.)
To find sum of three numbers 14, 27 and 13, we can have two ways:
- We may first add 14 and 27 to get 41 and then add 13 to it to get the total sum 54 or
- We may add 27 and 13 to get 40 and then add 14 to get the sum 54. Thus, (14 + 27) + 13 = 14 + (27 + 13)
This can be done for any three numbers. This property is known as the associativity of addition of numbers. Express this property which we have already studied in the chapter on whole numbers, in a general way, by using variables a, b and c.
The side length of the top of square table is x. The expression for perimeter is ______.
The expression for the number of diagonals that we can make from one vertex of a n sided polygon is ______.
The sum of the multiplication table of natural number ‘n’ is given by 55 × n. Find the sum of table of 7.
The sum of the multiplication table of natural number ‘n’ is given by 55 × n. Find the sum of table of 10.
