Missing Number (SSC CGL 2020 Tier -1)

In each column → (2nd term - 1st term) × 4 = 3rd term

{(15 - 4) × 4} = 44,

{(21 - 6) × 4} = 60

Similarly,

{(x - 7) × 4} = 68

⇒ x - 7 = 68 ÷ 4

⇒ x - 7 = 17

⇒ x = 17 + 7

x = 24

Hence, "24" is the correct answer.

On solving column-wise

{(22 × 1) - 4} = 18, {(18 × 2) - 4} = 32

{(32 × 1) - 8} = 24, {(24 × 2) - 8} = 40

{(7 × 1) - 2} = 5, {(5 × 2) - 2} = 8

Hence, "8" is the correct answer.

Column wise → ab + a + b = c

{(6 × 8) + 6 + 8} ⇒ 48 + 14 = 62

{(11 × 3) + 11 + 3} ⇒ 33 + 14 = 47

Similarly,

{(14 × 5) + 14 + 5} = 89

Hence, "5" is the correct answer.

Column wise → a × b = c

(3, 23, 69) → 3 × 23 = 69

(5, 27, 135) → 5 × 27 = 135

Similarly,

(7, 31, ?) → 7 × 31 = 217

Hence, "217" is the correct answer.

Row wise → a² + c = b

3² + 4 ⇒ 9 + 4 = 13

6² + 31 ⇒ 36 + 31 = 67

Similarly,

5² + 20 ⇒ 25 + 20 = 45

Hence, "45" is the correct answer.

Row wise → b + a = 5c

{(34 - 12) × 5} ⇒ 22 × 5 = 110

{(13 - 6) × 5} ⇒ 7 × 5 = 35

Similarly,

{(x - 9) × 5) = 60 ⇒ x - 9 = 60 ÷ 5 ⇒ x = 12 + 9 ⇒ x = 21

Hence, "21" is the correct answer.

Row wise → {(c - a)² - 1} = b

{(13 - 7)² - 1} ⇒ 6² - 1 ⇒ 36 - 1 = 35

{(14 - 9)² - 1} ⇒ 5² - 1 ⇒ 25 - 1 = 24

Similarly,

{(24 - 13)² - 1} ⇒ 11² - 1 ⇒ 121 - 1 = 120

Hence, "24" is the correct answer.

Column wise → a² - 4 = b and {(b × 4) - 2} = c

3² - 4 ⇒ 9 - 4 = 5 and {(5 × 4) - 2} ⇒ 20 - 2 = 18

8² - 4 ⇒ 64 - 4 = 60 and {(60 × 4) - 2} ⇒ 240 - 2 = 238

Similarly,

6² - 4 ⇒ 36 - 4 = 32 and {(32 × 4) - 2} ⇒ 128 - 2 = 126

Hence, "126" is the correct answer.

Row wise → {(b² + c²) ÷ 2} = a

{(9² + 3² )² ÷ 2} ⇒ {(81 + 9) ÷ 2} ⇒ 90 ÷ 2 = 45

{(10² + 12²)² ÷ 2} ⇒ {(100 + 144) ÷ 2} ⇒ 244 ÷ 2 = 122

Similarly,

{(6² + 14²) ÷ 2} ⇒ {(36 + 196) ÷ 2} ⇒ 232 ÷ 2 = 116

Hence, "14" is the correct answer.