Splification - Quantitative Aptitude
Q1. √ √(2500) + √(961) = ?2
(a) 22
(b) 32
(c) 42
(d) 52
Answer: (b) 32
√ √(2500) + √(961)
= √ (50 + 31)
= √ (81)
= √ (9 X 9) = 9 = 32
Q2. In a school, teachers agree to subscribe as maany rupees as there are subscribers. The total subscription being Rs. 625, the number of subscribers is
(a) 22
(b) 25
(c) 29
(d) 35
Answer: (b) 25
Let, the no. of subscribers be x
A/Q x2 = 625
⇒ x = √ 625 = √ 25 X 25 = 25
Q3. Two-fifth of the square of a certain number is 250. What is the number ?
(a) 20
(b) 22
(c) 25
(d) 35
Answer: (c) 25
Let, the number be x
A/Q 2/5 X x2 = 250
⇒ x2 = (250 X 5)/2
⇒ x2 = 125 X 5
⇒ x2 = 625
⇒ x = √625 = 25
Q4. Which smallest number must be added to 2203 to get a perfect square ?
(a) 6
(b) 8
(c) 10
(d) 13
Answer: (a) 6
4 ) 2203 ( 46
16
86) 603 ( 87
516
Required perfect square number = 472
No to be added = 472 - 2203 = 2209 - 2203 = 6
Q5. What is the smallest positive integer which when multiplied by 242, gives a perfect square ?
(a) 2
(b) 3
(c) 5
(d) 6
Answer: (a) 2
2|242 |
11|121 |
11 |
242 = 2 X 11 X 11
∴ Required no = 2
Q6. If a = √3/2 , then the value of (√(1 + a) + √(1 - a)) is
(a) √ 2
(b) √ 3
(c) √ 5
(d) √ 6
Answer: (b) √ 3
(√(1 + a) + √(1 - a))2 = 1 + a + 2√(1+a)(1-a) + 1 - a
= 2 + 2√(1 - a2)
= 2 + 2√(1 - 3/4)
= 2 + 2√(1/4)
= 2 + 2 X ½ = 3
∴ (√(1+a) + √(1 - a)) = √3
Q7. 1352 mangoes were distributed among a group of boys of a class. Each boy got twice as many mangoes as the number of boys in that group. The number of boys in the group was
(a) 22
(b) 23
(c) 25
(d) 26
Answer: (d) 26
Let the required no of boys be x
A/Q 2x X x = 1352
⇒ 2x2 = 1352
⇒ x2 = 676
⇒ x = 26
Q8. If x = (2 + √5) then x2 + 1/x2 = ?
(a) 5 + 3√5
(b) 5 + 4√5
(c) 7 + 4√5
(d) 7 + 3√5
Answer: (c) 7 + 4√5
x2 + | 1 | = (x + | 1 | )2 - 2 . x. 1/x |
x2 | x |
= (2 + √ 5)2 - 2
= 4 + 5 + 4√5 - 2
= 7 + 4√5
Q9. The length of diagonal of a square is 6 cm. The length of the side of the square is
(a) 3√2 cm
(b) 4√2 cm
(c) 5√2 cm
(d) 6√2 cm
Answer: (a) 3√2 cm
Let, length of the side of the square be x cm
A/Q x2 + x2 = 62
⇒ 2x2 = 36
⇒ x2 = 18
⇒ x = √18 = √(3 X 3 X 2) = 3√2 cm
Q10. By what least number must 21600 be multiplied to make it a perfect cube ?
(a) 8
(b) 10
(c) 12
(d) 13
Answer: (b) 10
2|21600 |
2|10800 |
2|5400 |
3|2700 |
3|900 |
3|300 |
10|100 |
10 |
21600 = 2 X 2 X 2 X 3 X 3 X 3 X 10 X 10
∴ Required no = 10
Practice Test Exam