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The numbers a, b, c and d satisfy the following equations: a + b + 3c + 4d = k; 5a = 3b = 2c = d. What is the smallest value for k for which a, b, c and d are all positive integers

5a = 3b = 2c = d. d must be a multiple of 5, 3 and 2, therefore the smallest possible value for d is 30. This sets a = 6, b = 10 and c = 152) a + b + 3c + 4d = 6 + 10 + 3x15 + 4x30 = 181 k = 181
Answered by Michael H. • Maths tutor
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Explain why excited atoms only emit certain frequencies of radiation after an electron collides with the atom

Radiation is emitted via photons2) Photon energy is governed by the equation E = hc/wavelength, where h = the Planck constant and c = the speed of light. Both h and c are constants3) Electrons have ...

Answered by Michael H. • Physics tutor

5138 Views

What does it mean that the UK has a common law legal system, and how is this different to a civil law one?

A common law system of laws, as used in the UK, predominantly develops through decisions made by judges in courts in the UK. This creates a body of binding laws based on precedent, whereby lower courts ar...

Answered by Eve F. • Law tutor

1495 Views

How would I answer a question on love/music in this unseen passage from The Mill on the Floss?

Great question. I've had a look over the passage and decided to focus on the extract below to give you an idea of how I'd go about approaching a close analysis. I think the key here is to 1) underline any...

Answered by Emily S. • English Literature tutor

2547 Views

Describe the structure of the human gas exchange system and explain how we breath in and out.

The human gas exchange system includes the trachea, the bronchioles and the alveoli. During inhalation (breathing in) the diaphragm contracts and the external intercostal muscles contract. This increases ...

Answered by Hajira I. • Biology tutor

20654 Views