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JKSSB Junior Assistant · Numerical Ability · 38 practice questions with answers and explanations: 13 Easy, 14 Medium, 11 Hard.
Sample questions
Sample Easy question 1
Find the average of all multiples of 5 from 5 to 45.
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- 25
- 27
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Answer: C. This is an arithmetic sequence from 5 to 45; the average of an AP equals the average of its first and last terms: (5+45)/2 = 25.
Sample Medium question 2
The average of 4 numbers is 20. If one number is removed, the average of the remaining 3 becomes 18. Find the removed number.
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- 26
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Answer: C. Original sum = 80, remaining sum = 54. Removed number = 80 - 54 = 26.
Sample Hard question 3
The average of 12 numbers is 18. If the average of the first 7 is 20 and the average of the last 6 is 15, find the 7th number.
- 14
- 15
- 16
- 17
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Answer: D. Total of 12 = 216. First 7 total = 140, last 6 total = 90. 7th number is counted in both groups, so 140 + 90 - 216 = 14 — the 7th number is 14.