NATS interview process

[K_ShowMe]

Manipulating Equations

Hi ya Q503,

You have to manipulate the equation slightly to simplify things further.

You have three options:

Option1 is (14 / 15 ) * 60

Option 2 is 14 *( 60 / 15 )

Option3 is (14*60) / 15

I would prefer option 2 to others, because 60 divide by 15 is 4 and multiplying it by 14 equals 56 minutes.

However, you don’t really have to work out 14/15 completely before using the result to multiply 60. you can work in fractions. That’s why it’s always a good idea to write out the equation in full.
So, if you encounter a fraction in your question, think of what you want to do with the result. In most cases, if it is not your final answer, you might be using it to multiply or divide another number. By bringing that number into the equation will perhaps simplify things. In as much as you want to be quick in your calculation, you also need to be accurate.

Take a look at this question for example:

(1) A packet of 20 sweeties cost 6.98 US Dollars. How much would 2 sweeties cost ?.

Solution: (6.98 ٪ 20)* 2 = 0.698 US Dollar.

Look at this now, if you decide to divide 6.98 by 20 in a bid to multiply the result by 2 , it will take you longer time to calculate than if
You divide 20 by 2 = 10 and then divide 6.98 by 10 = 0.698. U C wot I mean ?

0.698 US Dollar = 0.698 * 100 = 69.8 or 70 cents

Also take note of this: To divide a number by a fraction is equal to multiply that number by the inverse of the fraction.

For example.

(2) At what speed would My private jet cover 240 miles in 90 minutes ?
Solution : speed = distance / time
(240 * 2/3) = 160 mph is the same as 240 divide by 3/2 = 160 mph

So it’s good to rearrange equations for easy manipulations.
If you have done transfers functions, laplace transform or fourier analysis, you will know what I mean.

Cheers. I know, a lengthy note eh ?

Kingsley