Olympiad Test: Linear Equations In One Variable - 2 - Class 7 MCQ

 Let the two consecutive even number be x and x + 2.
∴ x + x +2 = 98
⇒ 2x + 2 = 98
⇒ 2x = 98 –2
⇒ 2x = 96

Let the whole number be x.
∴ 2x + 9 = 61
⇒ 2x = 61–9
⇒ 2x = 52

Let the present age be x years.
∴ 4 years ago, his age = (x – 4) years.
After 12 years, his age = (x + 12) years.
Hence, x  + 12 = 3(x – 4)
⇒ x + 12 = 3x –12

Let the present age of Niraj be x years.
His cousin’s age = x + 19
After 5 years,

⇒ 3x – 2x = 48 –15
⇒ x = 33

Given 8(2p – 5) – 6(3p – 7) = 1
⇒ 16p – 40 – 18p + 42 = 1
⇒ –2p + 2 = 1
⇒ –2p = 1– 2
⇒ –2p = –1
⇒ p = 1/2

Given equation is 
⇒ 0.6 y  + 0.8 = 0.56 y + 2.32 
⇒ 0.6 y –  0.56 y = 2.32 – 0.8
⇒ 0.04 y = 1.52

Let one angle be x. 
∴ Other angle (larger angle) = (x + 14)
Now,  x  + (x + 14) = 90°
⇒ 2x = 90 – 14
⇒ 2x = 76°

⇒ Larger angle is =  x + 14 = 38+14 = 52°

Therefore, the correct answer is C.

Let the odd numbers are x, x + 2, x + 4.
∴ x + x + 2 + x  + 4 = 147
⇒ 3x + 6 = 147
⇒ 3x = 147 – 6
⇒  3x = 141

Hence, the numbers are 47, 49, 51
∴ Smallest number = 47.

Let the base angle be x
Vertex angle = 3x.
∴ x + x + 3x = 180°
⇒ 5x = 180°

Vertex angle = 3×36° = 108°