Practice Model question set 1 - quantitative aptitude Online Quiz (set-1) For All Competitive Exams
Q-1) The smallest number by which 3888 must be divided so that the resulting number is a perfect square is
(a)
(b)
(c)
(d)
Resolving 3888 into its prime factors, we find that
3888=2×2×2×2×3×3×3×3×3
3888 = (2×2) × (2×2) × (3×3) × (3×3) ×3
Here we find that prime factor 3 is appearing alone.
So, if we divide 3888 by 3, we will get a perfect square number
Q-2) $(13)^2 - (4)^3$ - $√{676}$ + 2 = $(?)^2$
(a)
(b)
(c)
(d)
(e)
169 – 64 – $√{676} + 2 = (?)^2$
= 169 – 64 – 26 + 2 = $(?)^2$ = 171 – 90 = 81
∴ ? = 9
Q-3) The square of a natural number when subtracted from its cube results in 48. The number is
(a)
(b)
(c)
(d)
Let the natural number be 'x'.
∴ $x^3-x^2$=48
⇒$x^2$(x-1)=48
⇒$4^2$(4-1)=48
∴ x= 4
Q-4) $√{450 +890 + 685}$ = ?
(a)
(b)
(c)
(d)
(e)
$√{450 + 890 + 685} = √{2025}$ = 45
Q-5) $(13)^2 - (5)^2 - √676 +7 = (?)^2$
(a)
(b)
(c)
(d)
(e)
169 – 25 – 26 + 7 = $(?)^2 = 125 = ?^2⇒? = √125 = 5 √5$
Q-6) $(656 ÷ 164)^2 = √{?}$
(a)
(b)
(c)
(d)
(e)
$√{?}=4^2$ =16
∴? = 256
Q-7) You have a rectangular frame that is 40 cm by 60 cm. Can you put a square picture that has an area of 800 $cm^2$ completely inside the frame?
(a)
(b)
(c)
(d)
Q-8) What is the least number to be added to 2000 to make it a perfect square?
(a)
(b)
(c)
(d)
(e)
| 4 4 | 2000 16 | 45 |
| 85 5 | 400 425 | |
| - 25 |
Clearly, the required least number is 25.
Q-9) The smallest number by which 136 must be multiplied so that it becomes a perfect square is
(a)
(b)
(c)
(d)
Resolve 136 into prime factors and make group of two of each prime factor
136=2×2×2×17
136=(2×2)×2×17
We find that 2 and 17 doesn't appear in group of two. So, 136 has to be multiplied with 34 to make it a perfect square.
Q-10) ($^3$$√{795657}$ × 7) ÷ (3.8 × 5.5) = ?
(a)
(b)
(c)
(d)
(e)