Let the original price of a kilogram of sugar be Rs. X Now the new (reduced) price of sugar is x - (20/100)x = x - (x/5) = Rs. 4x/5 per kg. At the original price a purchaser can purchase (80/x) kg of sugar for Rs.80. At the new price, in Rs. 80 the purchaser … Read more

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In business correspondences it is essential to express ideas, facts and expression eloquently. Furthermore as time is of the essence almost always, the shorter the sentences and paragraphs are, the briefer will be the letter, memo or notice. Thus it saves both the reader's and writer's time, a commodity which is invaluable.

Using the First law of thermodynamics we know that the final temperature of the two will be identical. Let is call that temperature T degree Celsius.  Using the formula Q = m* c* Dt (where Dt means Delta T i.e. The change in temperature, m is the mass of substance and c is the specific … Read more

Sports such as football, cricket which are more watched / watched by more people can be considered to be 'in demand'. The TV channels thus 'supply' the people with live coverage and analysis of these sports. So these sports receive more sponsorships and the players get more salaries and incentives as compared to other sports … Read more

The moon orbits the Earth, which orbits the sun. So in a way the moon orbits both the Earth and the sun. In physics an orbit is not necessarily circular or elliptical in shape. The orbit of the moon around the sun is complicated as it is no longer a two body problem i.e. Along … Read more

Insecticides are supposed to harm only insects. However when sprayed onto soil or onto plants parts such as fruits and vegetables they might get absorbed by the roots and get stored with the starch inside the plant. As a result they get introduced in the food chain. These when consumed my living organisms have a … Read more

The atomic weights of Lead and Mercury are approx. 207 g / mol and 200 g / mol respectively. Compare this with the weigh of other metals in particular d block ones we observe that they are 4-5 times more heavy and hence the name heavy elements.

Using Pythagoras's theorem we can write,  (Hypotenuse)^2 = (Perpendicular)^2 + (Base)^2  Here the hypotenuse and base (shadow) are given and we have to find the length of the flag pole i.e. The perpendicular to the shadow.  So  (Perpendicular)^2 = (40)^2 - (32)^2  Using a62 - b^2 = (a+b)(a-b) we can write  (Perpendicular)^2 = (40+32)(40-32) = … Read more

We will have ti use the Heisenberg's uncertainty principle in this problem. So we have Dp. Dx >= h/4*pi where Dx denotes uncertainty in position and Dp the uncertainty in momentum. => Dx >= h / (4 * pi * m* Dv) where Dv is the uncertainty in velocity. Dv = (0.10/100) * 1.10 * … Read more

As the tiles are square shaped so the area of each tile is side x side. Each tile has a side of 60 cm = 0.6 meters. Number of tiles x  Area of each tile = Area of room So number of tiles = Area of room / Area of each tile Area of each … Read more

The expression  is - 2a^6 * b^-5                            -2a^(6-2) * c^3                          - a^4 * c^3 ------ =        ------    =      ------ 6c^-3 *b^-4 * a^2    … Read more

Radioactive decay obeys the law,C(t) = C(0) x e^(-Lt) where

Elements of set you are- the null element, q, r, s, t, you, v, w, x, y, z A - C = those elements which are not common to both these sets = null element (though this is common to all but if a set exists it has to contain this element), q, s, you … Read more

Let theta = x for typing purposes here. We will the formula of because (2x) = 2 ( because x)^2 - 1cos (4x) = because [2 * (2x)]. Let 2x = y. Now using the formula because (2y) = 2 ( because y)^2 - 1 = 2 [because (2x)]^2 - 1 Therefore because (2y) = … Read more

VT = Terminal Voltage, Rexternal = 5.6 ohms, Rinternal = Ri = 0.2 ohms Let the current in the circuit be I amperes. (1) VT = I Rexternal => I = VT / Rexternal = 10 / 5.60 = 1.786 A (2) Let the EMF of the battery be denoted by E. VT = E … Read more

Mass of water in the bottle = Mass of bottle with water - Mass of empty bottle                                       = 75 -30 = 45g. Under standard conditions, density of water is 1 g/cm^3. Hence, volume of water in … Read more

Aluminium 27 has the atomic number of 13. So a neutral atom of Al - 27 has 13 protons, 13 electrons and 14 neutrons.

An experimental bias is a defect in the experiment which favors a particular result over the other possible results. For example if you have a dice and you change the number three face to one. Now when you roll it (the experiment) the possible outcomes that you have will be different from the ones that … Read more

30 is composite number as it can be expressed as 1 x 2 x 3 x 5 i.e in terms of other prime numbers.