- Aptitude - Home
- Aptitude - Overview
- Quantitative Aptitude
Aptitude - Arithmetic Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to Basic Arithmetic. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Q 1 - If an A.P. have 4th term as 14 and 12th term as 70. What will be its common difference?
Answer : C
Explanation
Let's have first term as a, common difference is d then a + 3d = 14 ... (i) a + 11d = 70 ... (ii) Subtracting (i) from (ii) => 8d = 56 => d = 7
Q 2 - Find the number which being increased by 1 will be exactly divisible by 13, 15 and 19?
Answer : A
Explanation
LCM of 13, 15 and 19 is 3705 So the desired number is3705-1=3704
Q 3 - The difference between local and the face value of 8 in the numeral is 568012?
Answer : C
Explanation
8000 - 8 = 7992
Q 4 - If 123 is subtracted from the square of a number, the answer so obtained is 976. What is the number?
Answer : D
Explanation
Let the number be x. According to question: x2 - 123 = 976 or, x = 52
Q 5 - If first term of an A.P. is 6, its common difference is 5 then what is its 11th term?
Answer : D
Explanation
Here numbers are 14, 21, ..., 196 which is an A.P. Here a = 6, d = 5, Using formula Tn = a + (n - 1)d T11 = 6 + (11 - 1) x 5 = 56
Q 6 - What is the sum of all natural numbers starting from 75 up to 97?
Answer : D
Explanation
Here numbers are 75, 76, ..., 97 which is an A.P. Here a = 75, d = 1, l = 97 Using formula Tn = a + (n - 1)d Tn = 75 + (n - 1) x 1 = 97 => 74 + n = 97 => n = 97 - 74 = 23 Now Using formula Sn = (n/2)(a + l) ∴ Required sum = (23/2)(75+97) = 23 x 86 = 1978
Answer : A
Explanation
This is an infinite G.P. with a = 1 and r = 1/2. Sum of infinite G.P. = a/(1-r) = 1/(1-1/2) = 1/(1/2) = 2
Q 8 - If population of a bacteria doubles every 2 minutes. In how much minutes, it will grow from 1000 to 512000?
Answer : D
Explanation
Let the required growth be 1000, 2000, 4000,...512000. Here, a = 1000, r = 2, Tn = 512000 Using formula Tn = arn-1 => 1000 x 2n-1 = 512000 => 2n-1 = 512 = 29 => n - 1 = 9 => n = 10 ∴ time taken will be 2 x 9 = 18 minutes.
Answer : C
Explanation
Using formula (13 + 23 ... + n3) = [(1/2)n(n+1]2 (13 + 23 ... + 153) = [(15 x 16)/2]2 = 1202 = 14400 Using formula (1 + 2 + ... n) = [(1/2)n(n+1] ∴ (13 + 23 ... + 153) - (1 + 2 + ... + 15) = 14400 - (1/2) x 15 x 16 = 14400 - 120 = 14280
Q 10 - 12 + 22 ... + x2 = [x(x+1)(2x+1)]/6. What is 12 + 32 +... + 202?
Answer : A
Explanation
(12 + 32 ... + 202) = (12 + 22 ... + 202) - (22 + 42 ... + 192) Using formula (12 + 32 ... + n2) = [n(n+1)(2n+1)]/6 [20(20+1)(40+1)]/6 - (1 x 22 + 22 x 22 + 22 x 32 + ... + 22 x 92 + 22 x 102) = 2870 - 22(12 + 22 + ... + 192) = 2870 - 4(1 x 2 x 39)/6 = 2870 - 52 = 2818