CBSE Guess > Papers > Question Papers > Class X > 2009 > Mathematics > Mathematics

Or

A fraction becomes , if 2 is added to both numerator and denominator. If 3 is added to both numerator and denominator, it becomes. Find the fraction.

Sol. Let the fraction by
According to the question

3x + 6 = y + 2
3x – y = 2 – 6
3x – y = –4
3x + 4 = y …(i)

5x + 15 = 2y + 6
5x – 2y = 6 – 15
5x – 2y = – 9
5x – 2(3x + 4) = – 9
…[From (i)
5x – 6x – 8 = – 9
– x = – 9 + 8
– x = – 1
x = 1
From (i), y = 3(1) + 4 = 7
The fraction = =

Q. 19. Find the middle term of the A.P. 10, 7, 4, …, (– 62) .

Sol. 1 ^st term, a = 10
Common difference, d = 7 – 10 = – 3
a_n = – 62
a + (n – 1)d = – 62
10 + (n – 1) (– 3) = – 62
(n – 1) (– 3) = – 62 – 10 = – 72
n – 1 == 24
n = 24 + 1 = 25

Middle term = term term=13^th term

a_n = a + (n – 1)d a₁₃ = a + 12d
a₁₃ = 10 + 12(– 3) = 10 – 36 = – 26

Mathematics 2009 Question Papers Class X
Delhi		Outside Delhi		Compartment Delhi		Outside Delhi		Foreign
	Set 1 (PDF)		Set 1 (PDF)		Set 1		Set 1		Set 1 (PDF)
					Set 2		Set 2
					Set 3		Set 3