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There are 30 yellow sweets and 10 black sweets in a bag. Two sweets are taken out at random without replacement. Work out the probability that the two sweets are the same colour.

It is important before proceeding with the question to note down a few key facts. As can be seen by the question there are 40 sweets in total. With probability questions in general it can be easy to remember...
JT
Answered by James T. • Maths tutor
9755 Views

Write y = x^2 + 4x + 6 in the form y = (x + a)^2 + b. What is the minimum value of y?

This is an example of completing the square. Notice that when we expand y = (x + a)^2 + b we get y = x^2 + 2ax + a^2 + b. By comparing coefficients (ie, making sure the number x is multiplied by and the cons...
NS
Answered by Naomi S. • Maths tutor
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What is Fractional Distillation ?

Fractional distillation is the technique to separate different components present in the crude oil on the basis of their boiling points. Crude oil is a mixture of many useful hydrocarbons and it is very impo...
ML
Answered by Mahima L. • Chemistry tutor
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What are Enzymes ?

Enzyme are biological catalyst that speeds up the rate of the reaction without being used up. Enzymes speeds up the rate of chemical reaction by providing an alternative route to the reaction which lowering ...
ML
Answered by Mahima L. • Biology tutor
3538 Views

I don't understand why pressure changes the position of equilibrium in a reaction?

When thinking of pressure I like to think of two boxes joined together with the reactants in one and products in the other. When you make the boxes smaller (increase the pressure) the items in the box with m...
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Answered by Heather W. • Chemistry tutor
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