1 Crore+ students have signed up on EduRev. Have you? 
The ratio of the present ages of Sushma and Karishma is 6 : 7 respectively. The ratio of their ages 8 years hence would be 8 : 9 respectively. What would be the respective ratio of their ages after 12 years?
Let the present ages of Sushama and Karishma be 6x and 7x respectively.
or 56x + 64 = 54x + 72
x = 8/2 = 4
Required ratio
The solution of the equation xy = 0.9 and 11/2 (x+y)=1 is
The given system of equation is
x  y = 0.9 = 9/10 ...(1)
and 11 /2(x + y) = 1
⇒ x + y = 11/2 ...(2)
Adding (1) and (2), we get
2x = 9/10 + 11/2
⇒ 2x = 9 + 55/10 = 64/10
⇒ x = 32/10 = 3.2
When x = 3.2, we get
3.2  y = 0.9 (using(1))
⇒ y = 3.2  0.9 = 2.3
Thus, the solution of system of equation is x = 3.2 and y = 2.3
The ratio of two unequal sides of a rectangle is 1:2. If its perimeter is 24cm, then length of diagonal is
Let the sides of rectangle are x and 2x respectively. Then
2(x + 2x) = 24
⇒ x = 4
∴ Sides are 4 and 8 respectively.
Then length of diagonal
A boat takes 6 hours to travel from place M to N downstream and back from N to M upstream. If the speed of the boat in still water is 4 km/hr., what is the distance between the two places?
Total time = 6 hours
Speed of the boat in still water = 4 km/hr
Let the distance between M and N be D
and the speed of the stream be x
Since the speed of the stream (x) is not given, the distance D cannot be determined
Two wires have their lengths, diameters and resistivities, all in the ratio of 1 : 2. If the resistance of the thinner wire is 10 ohms, the resistance of the thicker wire is
Resistance is directly proportional to the length of the wire, its resistivity and inversely proportional to the crosssectional area.
WIRE I
Let the length = L
Resistivity = R
Diameter = D
∴ Total Resistance ∝ L x R/ D^{2}
WIRE II
Length = 2L
Resistivity = 2R
Diameter = 2D
∴ Total Resistance = 2L x 2R / 2D x 2D = LR/D^{2}
∴ WIRE I : WIRE II = LR/D^{2} : LR/D^{2} = 1 : 1
i.e. Resistance of WIRE Z_{B} is also 10Ω
select the correct combination of mathematical signs to replace * sign to balance the given equation.
24*3*2*12*3
Two trains 100 metres and 120 metres long are running in the same direction with speeds of 72 km/hr and 54 km/hr. In how much time will the first train cross the second?
Trains are moving in the same direction
So the relative speed with which the y pass each other = (72  54) km/hr = 18 km/hr
distance covered = sum of the lengths of trains
= 100 + 120 = 220m = 220/1000 km = 11/50 km
Required time = 11/50 x 1/18 x 3600 = 44 sec
Let the third propertional of 20 and 16 be x
Then 20, 16, x are in propertion
This means 20 : 16 = 16 : x
So, 20 x x = 16 x 16
x = 16 x 16 / 20 = 12.8
A certain sum was put at a certain rate of interest for 3 yrs. Had it been put at 2% higher rate, it would have fetched Rs 72 more. Find the sum.
At 2% more rate, the increase in SI for 3 years = Rs 72 (given)
So at 2% more rate the increase in SI for 1 year = 72/3 = Rs 24
i.e., Rs 24 is 2% of the invested sum
So 1% of the invested sum = 24/2 = 12
Therefore, the invested sum
= 12 x 100 = Rs 1200
Let PQ = 64 km A man starts from P and walks 32 km on first day, on second day he walks only 16 km, on third day he walks 8 km, on fourth day he walks just half, i.e. 4 km. He will reach Q in
Distance between PQ = 64 km
Distance covered on the 1st day = 64/2 = 32 km
Distance covered on the 2nd day = 32/2 = 16 km
Like wise Total distance covered = 32 + 16 + 8 + 4 + ..........
This is an infinite geometric series whose first term is 32 and common ratio = 1/2
∴ Sum of the infinite series = a/1  r
Where a is the first term and r common ratio = 32/1/2 = 64
Hence the man will never reach Q
Each of the following questions consists of two sets of figures. Figures 1, 2, 3 and 4 constitute the Problem Set while figures A, B, C, D and E constitute the Answer Set. There is a definite relationship between figures 1 and 2. Establish a similar relationship between figures 3 and 4 by selecting a suitable figure from the Answer Set.
In the following problem, out of the five figures marked 1, 2, 3, 4 and 5, four are similar in a certain manner. However, one figure is not like the other four. Choose the figure which is different from the rest.
The pins, equal in number to the number of sides in the main figure are attached to the midpoint of a side of the main figure in case of figures 2, 3, 4 and 5. In fig. 1, these pins are attached to a vertex of the main figure.
In the following questions, select a figure from amongst the four alternatives, which when placed in the blank space of fig. (X) would complete the pattern.
(i) K, L, M, N, O, P and Q are sitting along a circular table facing the centre.
(ii) L sits between N and O.
(iii) K is third to the left of O.
(iv) Q is second to the left of M, who is to the immediate left to P.
Q. Which of the following pairs has the first person sitting to the immediate left of the second person?
A solid cube has been painted yellow, blue and black on pairs of opposite faces. The cube is then cut into 36 smaller cubes such that 32 cubes are of the same size while 4 others are of the bigger size. Also, no face of any of the bigger cubes is painted blue.
Q. How many cubes have at least one face painted blue?
The figure is divided into three layers. The First layer in the front consisting of 16 cubes has:
(i) 4 central cubes having one face painted blue and all other faces uncoloured.
(ii) 4 corner cubes having one face blue, one face yellow, one face black and the remaining three faces uncloured
(iii) Out of the remaining cubes, 4 cubes have one face yellow and one face blue and all other faces
uncloured while 4 cubes have one face black and one face blue and all other faces uncoloured.
The second layer in the middle consisting of 4 cubes each of which has one face black and one
face yellow and all other faces uncoloured.
The third layer in the lear consisting of 16 cubes has exactly the same configuration as the first layer.
All the 16 cubes in the first layer and all the 16 cubes in the third layer have at least one face painted blue.
Thus, there are 16 + 16 = 32 such cubes
These questions are to be answered on the basis of the following table giving the thermal and hydel generation over the period 1991 to 1995 in terms of kWH per kw of installed capacity.
Q. The ratio of thermal and hydel installed capacity over the period 19911995 is nearly
These questions are to be answered on the basis of the following table giving the thermal and hydel generation over the period 1991 to 1995 in terms of kWH per kw of installed capacity.
Q. The average kWH generated per kW of installed capacity for hydel power generation was approximately:
These questions are to be answered on the basis of the following table giving the thermal and hydel generation over the period 1991 to 1995 in terms of kWH per kw of installed capacity.
Q. If the total installed capacity in the thermal sector in 1992 was 89×10^{5}kW, then how many kWH of energy was generated?
1 docs48 tests

Use Code STAYHOME200 and get INR 200 additional OFF

Use Coupon Code 
1 docs48 tests








