Question

In a school 50% of the students ore younger
then 10, 1/20 are 10 years old and 1/10 are older
then 10 brut younger then 12, the remaining, 70
students are 12 years or older. How many students
are 10 year old​

Answer 1

Answer:

20

Explanations:

Let total No. of students be x

50/100x + 1/20x + 1/10x + 70 = x

10/20x + 1/20x + 2/20x + 70 = x

13/20x + 70 = x

70 = (x - 13/20x)

70 = (20/20x - 13/20x)

70 = 7/20x

70 ÷ 7/20 = x

70 × 20/7 = x

200 = x

1/20 of x = 1/20 × x = 20