Question

A bag contains red marbles, green marbles and blue marbles only. The ratio of the number of marbles of each colour is red : green : blue = 12:5:2. There are 112 more red marbles than green marbles. Work out the number of blue marbles.​

Answer 1

Answer:

32

Step-by-step explanation:

let the number of green, red and blue marbles be: g, r and b

therefore,

r = g + 112            Eq 1

also, r/g = 12/5

or, r = 12*g/5

Put this value of r in equation 1. We get,

12*g/5 = g +112

Solving we get,

g = 80

Therefore, r = 80 + 112 = 192

Further, g/b = 5/2

or, b = g*2/5 = 80*2/5 = 32

Answer 2

Concept:

Fractions are used to describe ratios and proportions. A ratio is formed when a fraction is written as a:b, whereas a percentage says that two ratios are equal. Any two numbers can be used as a and b.

Find:

The number of blue marbles.

Solution:

Let the total number of red marbles be $12x$.

Let the total number of green marbles be $5x$.

Let the total number of blue marbles be $2x$.

$12x-5x=112\\7x=112\\x=16$

The number of blue marbles

$=2x\\=2*16\\=32$

Hence, the total number of blue marbles are $32$.

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