Splification - Quantitative Aptitude
Q21.
(1 + |
1 |
) ( 1 + |
1 |
) ( 1 + |
1 |
) |
= ? |
1 + x |
2 + x |
3 + x |
(a) (4+x) / (1+x)
(b) (2+x) / (4+x)
(c) (3+x) / (1+x)
(d) (3+x) / (5+x)
Answer: (a) (4+x)/(1+x)
1+x+1 |
X |
2+x+1 |
X |
3+x+1 |
1 + x |
2 + x |
3 + x |
= |
2+x |
X |
3+x |
X |
4+x |
1 + x |
2 + x |
3 + x |
Q22.
( |
1 |
+ |
1 |
+ |
1 |
+ |
1 |
) |
= ? |
1.4 |
4.7 |
7.10 |
10.13 |
(a) 3/12
(b) 4/13
(c) 4/15
(d) 5/13
Answer: (b) 4/13
1 |
[ |
3 |
+ |
3 |
+ |
3 |
+ |
3 |
] |
3 |
1.4 |
4.7 |
7.10 |
10.13 |
= |
1 |
[(1 - |
1 |
) + ( |
1 |
- |
1 |
) + ( |
1 |
- |
1 |
) + ( |
1 |
- |
1 |
)] |
3 |
4 |
4 |
7 |
7 |
10 |
10 |
13 |
Q23. If x/y =1/2 the (x3+y3)/(x3-y3) = ?
(a) - 9/7
(b) 7/9
(c) - 7/9
(d) 9/7
Answer: (a) - 9/7
x3+y3 |
= |
(x3/y3) + 1 |
x3-y3 |
(x3/y3) - 1 |
Q24.
(a) x+y x2 - y2
(b) x-y
(c) (x-y)/(x+y)
(d) (x+y)/(x-y)
Answer: (d) (x+y)/(x-y)
(x+y)2 |
= |
(x+y)(x+y) |
= |
(x+y) |
x2 -y2 |
(x+y)(x-y) |
(x-y) |
Q25. If a/b = 2/3, then (3a + 3b)/(3a - 3b) = ?
(a) 5
(b) -5
(c) 6
(d) -6
Answer: (b) -5
3a+3b |
= |
(3a/b) + 3 |
3a-3b |
(3a/b) - 3 |
= |
3.(a/b) + 3 |
3.(a/b) - 3 |
= |
3.(2/3) + 3 |
3.(2/3) - 3 |
= -5
Q26. If x+(1/y) = 1 and y+(1/z) = 1, then z+(1/x) = ?
(a) 1
(b) 11
(c) 111
(d) None of the above
Answer: (a) 1
x + |
1 |
= 1 => x = 1 - |
1 |
= |
y - 1 |
=> |
1 |
= |
y |
y |
y |
y |
x |
y-1 |
y + |
1 |
= 1 => |
1 |
= 1 - y => z = |
1 |
z |
z |
1-y |
Now z + |
1 |
= |
1 |
+ |
y |
x |
1-y |
y-1 |
Q27. If x+3y = 6 and xy = 4 then (3/x + 1/y) = ?
(a) 2/3
(b) 1(3/2)
(c) 3/2
(d) 2(2/3)
Q28.
245X245+245X230+230X230 |
= ? |
245X245X245 - 230X230X230 |
(a) 1/3
(b) 5/2
(c) 3/2
(d) 1/15
Answer: (d) 1/15
(245)2 + 245X230 + (230)2 |
(245)3 - (230)3 |
Formula |
a2+ab+b2 |
= |
a2+ab+b2 |
= |
1 |
a3 - b3 |
(a-b)(a2+ab+b2) |
a-b |
Q29.
If x+y+z = 0, then ( |
x2 |
+ |
y2 |
+ |
z2 |
) = ? |
yz |
zx |
xy |
(a) 1
(b) 2
(c) 3
(d) 33
Answer: (c) 3
If x+y+z = 0 then x3+y3+z3 = 3xyz
Now |
x2 |
+ |
y2 |
+ |
z2 |
= |
x3+y3+z3 |
yz |
zx |
xy |
xyz |
= 3
Q30. If a-b = 5 and a2+b2 = 30 then ab = ?
(a) 5/2
(b) 2/5
(c) 3/2
(d) 7/2
Answer: (a) 5/2
(a-b)2 = a2 + b2 - 2ab
=> 52 = 30 - 2ab
=> 25 - 30 = - 2ab
=> - 5 = - 2ab
=> ab = 5/2
Practice Test Exam