Having Trouble Learning Ratio?
Okay, your math teacher walked into your class with his belt on his tummy and his half shoe. Straight to the board he wrote #ratio and he turned with is already squeezed face saying "who among you knows ratio?" As usual, maths class is always silent as grave yard, No response. With frustration, he turned to the board and wrote what looks like jargons to you, explained in a shallow way, gave class work and you score zero. Well, here is another chance.
Ratio
Ratio is a comparison of two or more quantities that are alike.i.e you can't compare a dog to a book, same as you can't compare a car to a house. But you can compare a lorry to a truck in some way. The symbol for ratio is :
Example I| 2:3 is read as 2 ratio 3
Example 2| The ratio of red button to blue button will be red button:blue button.
If you look closely, red button came first before blue button in the answer because red button came before blue button in the question.
NB: Ratios can also be written in fraction and vice versa i.e 2:3 = 2/3 but 2:3 is not equal to 3/2
Exercise 1
Complete to give equal ratios:
3 : 4 = [ ] : 16
Recall ratios can be written as fractions
• 3:4 can be written as 3/4
• [ ]:16 can be written as [ ]/16
I.e 3/4 = [ ]/16
Check the picture below for further and understandable calculation.
Any trouble? Please let me know in the comment section.
Exercise II
Express each of these as ratio to the lowest term.
(a) 3cm : 36cm (b) 75k : N2 (c) 25min : 1h20min
Solution
(a) 3cm : 36cm
Ratio can be written in fraction
= 3/36
Lowest term = 1/12
Answer = 1cm : 12cm
(b) 75K : N2
Recall, you can't compare ratios with different unit. It's either you convert K(kobo) to N(naira) or N to K.
It's best you convert Naira to Kobo.
To do that;
We know 1 Naira = 100kobo
Therefore,
2 Naira = 200kobo (so far N1 = 100k, N2 = 200k)
75K : 200K
They are both in Kobo, so we solve,
=75/200
Lowest term = 5/ 8
Answer= 5k : 8k
Check the picture below for simplified calculations
(3) 25mins : 1hr 20mins
As we already know, we can't work with mins and hour. They are not the same. So we convert hour to minutes.
1hr = 60 minutes
Therefore 1hr 20mins = 60 minutes + 20 minutes
Which is 80 minutes.
1hr 20minutes = 80 minutes
They are both in minutes, so we can solve
25mins : 80mins
= 25/80
Lowest term= 5/16
Answer= 5mins : 16 minutes
Exercise III
Mr and mrs shuaibu bought some shares for their three children Jumai, Danladi and Kabiru in the ratio 7 : 5 : 3. If the total shares bought were 90000 units, how many units did each receive?
Solution
Recall, respectively i.e
Jumai came first so as 7
Danladi came second so as 5
Kabiru came third so as 3
Parameters
Jumai = 7
Danladi = 5
Kabiru = 3
To solve, sum up the ratio. Which is 7 + 5 + 3 = 15
Total = 15
So far the question requests how much all recieved.
That will be
Jumai = Jumai/Total number of ratio x 90000
Danladi = Danladi/Total number of ratio x 90000
Kabiru = Kabiru/ Total number of ratio x 90000
Calculations
Jumai = 7/15 x 90000
= 42,000 units
Danladi = 5/15 x 90000
= 30,000 units
Kabiru = 3/15 x 90000
= 18,000 units
i.e Jumai received 42,000 units
Danladi recieved 30,000 units
Kabiru recieved 18,000 units
Voila!!
Any question? Let me know in the comment section. I'll be using YouTube to post videos, although the link will be here for you to watch as i teach live.
P.A
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