alleryStart learning →The smallest prime number is
- 1
- 2
- 3
- 5
Show answer and solution
Correct answer: B. 2
2 is the smallest prime (and the only even prime).
1 is neither prime nor composite by convention.
Indian Air Force Group Z Number System LCM HCF — practice questions
Explore 32 free Number System LCM HCF questions in Indian Air Force Group Z Quantitative Aptitude. Open each question or exercise to read its content, reference answers and available explanation.
Practise Number System LCM HCF with Quill →Number System LCM HCF questions and exercises with answers
Showing questions 1–30 of 32.
The smallest prime number isRead the answer and worked solution →How many positive divisors does 36 have?Read the answer and worked solution →What is the unit digit of 7^25?Read the answer and worked solution →The sum of the first 20 natural numbers isRead the answer and worked solution →Which of the following is divisible by 11?Read the answer and worked solution →The remainder when 2^10 is divided by 7 isRead the answer and worked solution →The LCM of 12, 15 and 20 isRead the answer and worked solution →The HCF of 48 and 72 isRead the answer and worked solution →The product of two numbers is 720 and their HCF is 12. Their LCM isRead the answer and worked solution →The largest number that divides 280 and 1245 leaving remainders 4 and 3 respectively isRead the answer and worked solution →If 20% of x = 60, then 40% of x isRead the answer and worked solution →In an exam, 30% candidates failed. If 350 students passed, the total number of candidates wasRead the answer and worked solution →Two numbers are 25% and 30% less than a third number. The first as a percent of the second isRead the answer and worked solution →A's salary is reduced by 10% and then increased by 10%. Net change isRead the answer and worked solution →A man sells two articles at Rs 480 each. On one he gains 20%, on the other he loses 20%. His overall loss isRead the answer and worked solution →The marked price of an article is 25% above CP. After a 10% discount, the profit percent isRead the answer and worked solution →A trader buys 12 oranges for Rs 10 and sells 10 oranges for Rs 12. His profit percent isRead the answer and worked solution →Pipes A and B can fill a tank in 12 and 15 hours respectively. Pipe C empties it in 20 hours. With all three open, the tank fills inRead the answer and worked solution →Two trains, 120 m and 80 m long, run in opposite directions at 36 km/h and 54 km/h. Time to cross each other isRead the answer and worked solution →A and B can do a piece of work in 10 days. B and C in 15 days. A and C in 12 days. A alone can do it inRead the answer and worked solution →A train running at 60 km/h crosses a man standing on the platform in 12 seconds. The length of the train isRead the answer and worked solution →A can do a piece of work in 20 days, B in 30 days. Together they can do it inRead the answer and worked solution →At what rate per annum will Rs 1200 amount to Rs 1452 in 2 years at compound interest (compounded annually)?Read the answer and worked solution →A sum amounts to Rs 1500 in 5 years and Rs 1800 in 8 years at simple interest. The principal isRead the answer and worked solution →In a triangle, two angles are 65 degrees and 75 degrees. The third angle isRead the answer and worked solution →The value of sin 30 degrees + cos 60 degrees isRead the answer and worked solution →If tan(theta) = 1, then theta isRead the answer and worked solution →The length of the diagonal of a rectangle 6 cm by 8 cm isRead the answer and worked solution →If a + 1/a = 5, then a^2 + 1/a^2 isRead the answer and worked solution →The volume of a cylinder of radius 7 cm and height 10 cm is (use pi = 22/7)Read the answer and worked solution →
Worked practice questions
How many positive divisors does 36 have?
- 6
- 7
- 8
- 9
Show answer and solution
Correct answer: D. 9
36 = 2^2 x 3^2. Number of divisors = (2+1)(2+1) = 9. Divisors: 1, 2, 3, 4, 6, 9, 12, 18, 36.
What is the unit digit of 7^25?
- 1
- 3
- 7
- 9
Show answer and solution
Correct answer: C. 7
Unit digits of 7^n cycle: 7, 9, 3, 1, 7, 9, 3, 1... (period 4).
25 mod 4 = 1, so unit digit matches 7^1 = 7.
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