The ratio of boys to girls in a class is 7 to 3. Among the options below, an acceptable value for the total number of students in the class is:
Ratio Understanding
The ratio of boys to girls is given as 7 to 3 (7:3). This means that for every group of students represented by this ratio, there are 7 parts boys and 3 parts girls.
Calculating Total Parts
The total number of parts in the ratio is the sum of the parts for boys and girls:
$ \text{Total Parts} = 7 (\text{boys}) + 3 (\text{girls}) = 10 \text{ parts} $
Determining Acceptable Total Students
The total number of students in the class must be divisible by the total number of parts (10). This ensures that the number of boys and girls are whole numbers, maintaining the 7:3 ratio.
We need to find which option is a multiple of 10:
- Option 1: 21 is not divisible by 10.
- Option 2: 37 is not divisible by 10.
- Option 3: 50 is divisible by 10 ($50 \div 10 = 5$).
- Option 4: 73 is not divisible by 10.
Therefore, 50 is the only acceptable value for the total number of students.
Important Questions from Ratio and Proportion
The cost of a diamond is directly proportional to the square of its weight. The cost of a 14 gm diamond is Rs. 2560. This diamond got broken down into two pieces in the ratio of 5 ∶ 9. How much loss percent is incurred due to this breakage ? (Correct to two decimal places)
Atul purchased Bread costing Rs.20 and gave a 100 rupee note to the shopkeeper. The shopkeeper gave the balance money in coins of denomination Rs.2, Rs.5 and Rs.10. If these coins are in the ratio 5 ∶ 4 ∶ 1, then how many Rs.5 coins did the shopkeeper give?
A person divides a certain amount among his three sons in the ratio of 3 ∶ 4 ∶ 5. If he had divided this amount in the ratio of 1/3,1/4,1/5, his son, who had got the lowest share earlier, would get Rs.1,188 more. Find the amount (in Rs).
In a school 3/8 of the number of students are girls and the rest are boys. One-third of the number of boys are below 10 years and 2/3 the number if girls are also below 10 years. If the number of students of age 10 or more years is 260. then the number of boys in the school is:
If a : b : c = \(\frac{1}{4} : \frac{1}{3} : \frac{1}{2}, \) then \( \ \frac{a}{b} : \frac{b}{c} : \frac{c}{a} = ?\)
