Question

How do you solve a ratio problem?

Answer 1

A ratio is always expressed as "a:b" which is used as a fraction ab for calculation purposes and a and b are two quantities in the same units. There are possibilities for a ratio to have more than 2 terms like a:b:c and so on.

Let’s choose a ratio problem and see how we solve it

A bag has some yellow and some white sweets, the ratio of yellow sweets to white sweets is 2:3. If the bag contains 60 white sweets, how many yellow sweets are there?

Step 1: Assign the unknown quantity of yellow sweets to a variable 'x'

Step 2: Express ratio as a fraction

$2:3 = \frac{2}{3} = \frac{No.\ of\ yellow\ sweets}{No.\ of \ white\ sweets} = \frac{x}{60}$

Step 3: Solve for x by cross multiplication

$\frac{2}{3}= \frac{x}{60}$

2 × 60 = 3 × x  

3x = 120  

Step 4: Keep x in LHS and move 3 to RHS. Because x is multiplied by 3 in the LHS, when we move to RHS, it turns to be a divisor which divides 120

$x = \frac{120}{3} = 40$  

There are 40 yellow sweets