Question
In a class, the ratio of number of boys to number of
girls is 5:3. If 2 boys joined the class and 3 girls left the class, then the ratio becomes 7:4. Find the actual number of girls in the class.Solution
Let initially the number of boys and girls be 5x and 3x, respectively.
(5x + 2) : (3x − 3) = 7 : 4
Or, 4(5x + 2) = 7(3x − 3)
Or, 20x + 8 = 21x − 21
Or, x = 29
Therefore, number of girls = 3 × 29 = 87Â
More Ratio and proportion Questions
√196 + (0.25 × 144) + 19 = ? + 72
81% of 2300 – 34% of 550 = ?
 (5/8) × 480 + (3/9) × 450 = (5/2) × ?
Simplify the following expressions and choose the correct option.
{ (15/2) * 16 } ÷ (5/2) + 9
What is the value of (152+82) ÷17
15 × 18 + 25 × 12 + 30 × 24 = ?% of 1720
36% of 250 + 26 ÷ 2 × ? = 207
Find the value of 45 - 3 x (4 of 6 + 12 ÷ 3 × 6 – 4 × 5) + 6.
600 ÷ 8 + 12 % of 250 + ? * 14 = 50 * √49
19 × ? =361 ÷ 19
