Advertisements
Advertisements
प्रश्न
9 pens and 5 pencils cost Rs.32, and 7 pens and 8 pencils cost Rs.29. Find the unit price for each pen and pencil.
Advertisements
उत्तर
Let the unit price for each pen = Rs. x
and the unit price for each pencil = Rs. y
According to given information, we have
9x + 5y = 32 ....(i)
7x + 8y = 29 ....(ii)
Multiplying eqn. (i) by 8 and eqn. (ii) by 5, we get
72x + 40y = 256 ....(iii)
35x + 40y = 145 ....(iv)
Subtracting eqn. (iv) from eqn. (iii), we get
37x = 111
⇒ x = 3
⇒ 9(3) + 5y = 32
⇒ 27 + 5y = 32
⇒ 5y = 5
⇒ y = 1
Thus, the unit price for each pen is rs. 3 and that for each pencil is Rs.1.
APPEARS IN
संबंधित प्रश्न
Solve the following simultaneous equation :
8v - 3u = 5uv
6v - 5u = -2uv
Solve the following simultaneous equations:
65x - 33y = 97
33x - 65y = 1
Solve the following simultaneous equations:
103a + 51b = 617
97a + 49b = 583
Solve the following pairs of equations:
`x/(3) + y/(4)` = 11
`(5x)/(6) - y/(3)` = -7
Solve the following pairs of equations:
`(x + y)/(xy)` = 2
`(x - y)/(xy)` = 6
Solve the following pairs of equations:
`(xy)/(x + y) = (6)/(5)`
`(xy)/(y - x)` = 6
Where x + y ≠ 0 and y - x ≠ 0
The ratio of two numbers is `(2)/(5)`. If 4 is added in first and 32 is subtracted from the second, the ratio becomes the reciprocal of the original ratio. Find the numbers.
An eraser costs Rs. 1.50 less than a sharpener. Also, the cost of 4 erasers and 3 sharpeners is Rs.29. Taking x and y as the costs (in Rs.) of an eraser and a sharpener respectively, write two equations for the above statements and find the value of x and y.
A person goes 8 km downstream in 40 minutes and returns in 1 hour. Determine the speed of the person in still water and the speed of the stream.
A solution containing 12% alcohol is to be mixed with a solution containing 4% alcohol to make 20 gallons of solution containing 9% alcohol. How much of each solution should be used?
