Question

The ratio of the students in schools A, B and C is 5 : 4 : 7. If the number of students in the schools are increased by 20%, 25% and 20% respectively, what would be the new ratio of the students in schools A, B and C?

a. 5:5:7
b. 30:25:42
c. 30:20:49
d. cannot be determined
e. none of these

Answer 1

The new ratio of the students in schools A, B, and C after increasing the number of students in each school by certain percentages can be calculated by finding the new number of students in each school and then simplifying the ratio. The correct answer is b. 30:25:42.

Step-by-step explanation:

To find the new ratio of the students in schools A, B, and C after increasing the number of students by 20%, 25%, and 20% respectively, we can calculate the new number of students in each school and then find the new ratio. Let's assume the original number of students in schools A, B, and C are 5x, 4x, and 7x respectively. After increasing the number of students, the new number of students in A, B, and C will be (5x + 20%), (4x + 25%), and (7x + 20%) respectively.

Now let's simplify these expressions. Adding 20% to 5x is the same as multiplying 5x by 1.2. Adding 25% to 4x is the same as multiplying 4x by 1.25. Adding 20% to 7x is the same as multiplying 7x by 1.2. So the new number of students in A, B, and C will be 6x, 5x, and 8.4x respectively.

Therefore, the new ratio of students in schools A, B, and C is 6 : 5 : 8.4, which can be simplified to 30 : 25 : 42. So the correct answer is b. 30:25:42.