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What should come in place of question mark (?) in the following question?
0.0135 of 270 + 0.07 of 441 = ?
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0.0135 of 270 + 0.07 of 441
= 3.645 + 30.87
= 34.51
What should come in place of question mark '?' in the following questions?
a p(q - r) × aq(r - p) × ar(p - q) = ?
Solve the given question, using following laws of indices,
Laws of Indices,
1-: am × an = a{m + n}
2-: am ÷ an = a{m - n}
3-: [(am)n] = amn
(3a + 1 9a + 2 27a) ÷ (3a - 1 9a 27a + 1) = ?
When 3675 is divided by the square of a number and the answer so obtained is multiplied by 37, the final answer obtained is 2775. What is the number?
Let, the number is = x
According to problem,
⇒ (3675/x2) × 37 = 2775
⇒ 3675/x2 = 2775/37
⇒ 3675/x2 = 75
⇒ x2 = 49
⇒ x = 7
A bottle full of Brandy contains 40% alcohol. A part of this Brandy was replaced by another one having 19% alcohol and the percentage now became 26%. What was the quantity of Brandy replaced?
Concentration of Alcohol in the first bottle = 40%
Concentration of Alcohol in the second bottle = 19%
We know that,
For first bottle,
26 - 19 = 7
For second bottle,
40 - 26 = 14
Hence the ratio is 1 ∶ 2.
The part of Brandy replaced = 2/3
∴ The part of Brandy replaced is 2/3
In the given question,two equations numbered l and II are given. You have to solve both the equations and mark the appropriate answer
I) x2 – 15x + 56 = 0
II) y2 – 4y - 5 = 0
From the given data,
⇒ x2 – 15x + 56 = 0
⇒ x2 - 7x - 8x + 56 = 0
⇒ x (x - 7) - 8 (x - 7) = 0
⇒ (x - 7)(x - 8) = 0
∴ x = 7 and x = 8
Also given that y2 – 4y - 5 = 0
⇒ y2 + y - 5y - 5 = 0
⇒ y (y + 1) - 5 (y + 1) = 0
⇒ (y - 5)(y + 1) = 0
∴ y = 5 and y = - 1
When x = 7 and y = 5, then x > y
When x = 7 and y = - 1, then x > y
When x = 8 and y = 5, then x > y
x = 8 and y = - 1, then x > y
∴ x > y
I) x2 + 6x + 9 = 0
II) y2 + 4y + 4 = 0
⇒ x2 + 6x + 9 = 0
⇒ x2 + 3x + 3x + 9 = 0
⇒ x (x + 3) + 3 (x + 3) = 0
⇒ (x + 3)(x + 3) = 0
∴ x = - 3
Also from the given data,
⇒ y2 + 4y + 4 = 0
⇒ y2 + 2y + 2y + 4 = 0
⇒ y (y + 2) + 2 (y + 2) = 0
⇒ (y + 2)(y + 2) = 0
∴ y = - 2
When x = - 3 and y = - 2, then x < y
Two trains A and B are running in the same direction at 36 km/h and 54 km/h, respectively. It takes 2 minutes for train B to completely overtake train A. If the length of train A is 250 m, find the length of the other train.
Speed of train A, SA = 36 km/h = 36 × (1000/3600) m/s = 10 m/s
Speed of train A, SB = 54 km/h = 54 × (1000/3600) m/s = 15 m/s
Length of train A, La = 250 m
Time taken for train B to overtake train A = 2 min = 120 s
Let the length of train B be Lb.
Time taken to overtake train A by train B = (La + Lb)/(SB – SA)
⇒ (250 + Lb)/(15 – 10) = 120
⇒ 250 + Lb = 600
⇒ Lb = 350 m
∴ length of train B is 350 m.
A part of Rs.12000 is lent to Ram at 7% per annum and the rest was lent to Shyam at 3% per annum. If the total simple interest received from both parts in 5 years was Rs. 2000. How much amount was lent to Ram?
We know the formula for calculating Simple Interest.
SI = (P × r × t)/100
Where,
SI = Simple Interest
P = Principal
r = Rate of interest (in percentage)
t = Time period
Total amount lent = Rs. 12000
Rate of interest for Ram = 7%
Rate of interest for Shyam = 3%
t = 5 years
Total Simple interest received = Rs. 2000
Let the amount lent to Ram be Rs. x.
⇒ Amount lent to Shyam = Rs. (12000 - x)
So,
[(x × 7 × 5)/100] + [{(12000 - x) × 3 × 5}/100] = 2000
⇒ 35x + 180000 - 15x = 200000
⇒ 20x = 20000
⇒ x = Rs. 1000
∴ The amount lent to Ram = Rs. 1000
A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cms side. What is of the ratio the total surface areas of the smaller cubes and the large cube?
We know that, volume of a cube = a3
Volume of cubes of 3 cm, 4 cm and 5 cm sides = 33 + 43 + 53 cm3
= 27 + 64 + 125 = 216 cm3
Surface area of the smaller cubes = 6(9 + 16 + 25) = 6 × 50 = 300 cm2
Since the large cube is obtained by melting the three smaller cubes,
Thus, volume of larger cube = sum of volumes of three smaller cubes = 216 cm3
Side of larger cube aa = ∛216 cm = 6 cm
Surface area of larger cube = 6 × a2 cm2, where a = length of each side of a cube
= 6 × 62 = 216 cm2
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