Number Series Questions – Practice Set 1 (With Detailed Solutions)

Note: Since the MCQs and options change after refreshing the page, questions and answers are provided without options and fixed order.

Q1: 3, 6, 11, 18, 27, ?

Answer: 38

Explain: Differences are increasing odd numbers: +3, +5, +7, +9, +11. So, (27 + 11) = 38.✅

Q2: 120, 99, 80, 63, 48, ?

Answer: 35

Explain: Each term is (n² - 1) with n = 11, 10, 9, 8, 7, ... So, (6² - 1) = 35.✅

Q3: 2, 5, 10, 17, 26, ?

Answer: 37

Explain: Pattern is +3, +5, +7, +9, +11 (odd numbers). So, (26 + 11) = 37.✅

Q4: 2, 3, 5, 8, 12, 17, ?

Answer: 23

Explain: Numbers increase by +1, +2, +3, +4, +5, ... So, (17 + 6) = 23.✅

Q5: 13, 17, 25, 41, 73, ?

Answer: 137

Explain: Differences double: +4, +8, +16, +32, ... So, (73 + 64) = 137.✅

Q6: 90, 87, 81, 72, 60, ?

Answer: 45

Explain: Differences are -3, -6, -9,-12, ... So, (60 - 15) = 45.✅

Q7: 4, 9, 19, 39, 79, ?

Answer: 159

Explain: Differences double: +5, +10, +20, +40, ... So, (79 + 80) = 159.✅

Q8: 1, 2, 6, 24, 120, ?

Answer: 720

Explain: Pattern is factorial-like: x2, x3, x4, x5, ... So, 120 x 6 = 720.✅

Q9: 7, 14, 28, 56, 112, 224, ?

Answer: 448

Explain: Each term is multiplied by 2. So, 224 x 2 = 448.✅

Q10: 125, 80, 45, 20, ?

Answer: 5

Explain: Differences are (-45), (-35), (-25), ... So, (20 - 15) = 5.✅

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