Question

If Rudra scored 10 marks in his mathematics test out of 30 marks, 9 times these marks would have been the square of his actual marks. How many marks did he get in the test?​

Answer 1

Answer:

15 marks

Step-by-step explanation:

Let rudra had scored x marks in the test of Mathematics.

According to the question, If she scored 10 marks more=> x+10

then 9 times of the marks = square of actual marks

So

9(10 + x) = x²

x² - 9x- 90 = 0

x²-15x + 6x - 90 = 0

x(x - 15) + 6(x − 15) = 0

(x − 15) (x + 6) = 0

so,

x - 15 = 0

x=15

or

x+6=0

x = -6

Neglect x = -6

So, marks that rudra scored are = 15

Verification:

= 9(15 + 10)

= 9 × 25

=>225 = (15)² = 225

hope you understand it. happy to help you