Question

1. Two numbers are in the ratio 4:7. If their sum is 143, find the numbers.
2. The ratio of number of boys and number of girls in a school is 7:5. If the total number of students in the school is 480, find the number of boys.
3. Compare the following and put >,< or =.
a) 17:23 and 5:9
b) 7:5 and 23:30
c) 16:24 and 2:3
d) 25:4 and 50:24​

Answer 1

Step-by-step explanation:

1. 4:7 ; Sum of the numbers = 143

143 / (4+7) = 143 / 11 = 13

4 x 13 = 52 ; 7 x 13 = 91

Therefore, the two numbers are = 52 and 91.

2. 7:5 ; Total number of students = 480

480 / (7+5) = 480 / 12 = 40

7 x 40 = 280 ; 5 x 40 = 200

Therefore, the number of boys is 280.