6.
If a = 0.1039, then the value of 4a2 – 4a + 1 + 3a is:
A. 0.1039 B. 0.2078
C. 1.1039 D. 2.1039
Answer & Explanation
Answer: Option C
Explanation:
4a2 – 4a + 1 + 3a = (1)2 + (2a)2 – 2 x 1 x 2a + 3a
= (1 – 2a)2 + 3a
= (1 – 2a) + 3a
= (1 + a)
= (1 + 0.1039)
= 1.1039
7.
If x = 3 + 1 and y = 3 – 1 , then the value of (x2 + y2) is:
3 – 1 3 + 1
A. 10 B. 13
C. 14 D. 15
Answer & Explanation
Answer: Option C
Explanation:
x = (3 + 1) x (3 + 1) = (3 + 1)2 = 3 + 1 + 23 = 2 + 3.
(3 – 1) (3 + 1) (3 – 1) 2
y = (3 – 1) x (3 – 1) = (3 – 1)2 = 3 + 1 – 23 = 2 – 3.
(3 + 1) (3 – 1) (3 – 1) 2
x2 + y2 = (2 + 3)2 + (2 – 3)2
= 2(4 + 3)
= 14
8.
A group of students decided to collect as many paise from each member of group as is the number of members. If the total collection amounts to Rs. 59.29, the number of the member is the group is:
A. 57 B. 67
C. 77 D. 87
Answer & Explanation
Answer: Option C
Explanation:
Money collected = (59.29 x 100) paise = 5929 paise.
Number of members = 5929 = 77.
9.
The square root of (7 + 35) (7 – 35) is
A. 5 B. 2
C. 4 D.
35
Answer & Explanation
Answer: Option B
Explanation:
(7 + 35)(7 – 35) = (7)2 – (35)2 = 49 – 45 = 4 = 2.
10.
If 5 = 2.236, then the value of 5 – 10 + 125 is equal to:
2 5
A. 5.59 B. 7.826
C. 8.944 D. 10.062
Answer & Explanation
Answer: Option B
Explanation:
5 – 10 + 125 = (5)2 – 20 + 25 x 55
2 5 25
= 5 – 20 + 50
25
= 35 x 5
25 5
= 355
10
= 7 x 2.236
2
= 7 x 1.118
= 7.826