Advertisements
Advertisements
प्रश्न
The ratio of passed and failed students in an examination was 3 : 1. Had 30 less appeared and 10 less failed, the ratio of passes to failures would have been 13 : 4. Find the number of students who appeared for the examination.
Advertisements
उत्तर
Let the number of passed students be x and the number of failed students be y.
According to the question,
`x/y = (3)/(1)`
⇒ x = 3y ....(i)
Now, if 30 less appeared and 10 less failed, then we have
Number of students appeared = x + y - 30
number of failed students = y - 10
∴ number of passed students = x - 20
⇒ `(x - 20)/(y - 10) = (13)/(4)`
⇒ 4x - 80 = 13y - 130
⇒ 4x - 13y = -50
⇒ 4(3y) - 13y = -50 ...[From (i)]
⇒ 12y - 13y = -50
⇒ -y = -50
⇒ y = 50
⇒ x = 3 x 50 = 150
⇒ x + y
= 150 + 50
= 200
Hence, 200 students appeared for the examination.
APPEARS IN
संबंधित प्रश्न
Solve the pair of linear (simultaneous) equations by the method of elimination by substitution:
8x + 5y = 9
3x + 2y = 4
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution :
2x - 3y = 7
5x + y= 9
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution:
2x + 3y = 8
2x = 2 + 3y
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution:
6x = 7y + 7
7y - x = 8
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution :
y = 4x - 7
16x - 5y = 25
Solve the following pair of linear (simultaneous) equation by the method of elimination by substitution:
1.5x + 0.1y = 6.2
3x - 0.4y = 11.2
Solve the following pair of linear (simultaneous) equation using method of elimination by substitution:
3x + 2y =11
2x - 3y + 10 = 0
Solve the following simultaneous equations by the substitution method:
0.5x + 0.7y = 0.74
0.3x + 0.5y = 0.5
Solve the following simultaneous equations by the substitution method:
3 - (x + 5) = y + 2
2(x + y) = 10 + 2y
Solve the following simultaneous equations by the substitution method:
7(y + 3) - 2(x + 2) = 14
4(y - 2) + 3(x - 3) = 2
Solve the following pairs of equations:
`(6)/(x + y) = (7)/(x - y) + 3`
`(1)/(2(x + y)) = (1)/(3( x - y)`
Where x + y ≠ 0 and x - y ≠ 0
The sum of four times the first number and three times the second number is 15. The difference of three times the first number and twice the second number is 7. Find the numbers.
A father's age is three times the age of his child. After 12 years, twice the age of father will be 36 more than thrice the age of his child. Find his present age.
* Question modified
In a ABC, ∠A = x°, ∠B = (2x - 30)°, ∠C = y° and also, ∠A + ∠B = one right angle. Find the angles. Also, state the type of this triangle.
Solve by the method of elimination
`x/10 + y/5` = 14, `x/8 + y/6` = 15
Solve by the method of elimination
3(2x + y) = 7xy, 3(x + 3y) = 11xy
Solve by the method of elimination
13x + 11y = 70, 11x + 13y = 74
Five years ago, a man was seven times as old as his son, while five year hence, the man will be four times as old as his son. Find their present age
