Question

16. A man bought a certain number of articles of the same kind for Rs. 900. Thirteen of them broke, but he
made a profit of Rs. 30 by selling the rest at Rs. 3 above cost price. How many did he buy?
(a) 100
(b) 120
(c) 75
​

Answer 1

Answer:

If ax^2+bx+c=0

X=[-b+-(b^2-4ac)^1/2)]/2a

X=[-(-23 )+_ ((-23)^2 - (4×1×3900))^1/2]/2

X=[-(-23 )+_ ((529-(-15600)^1/2]/2

It gives us either (23+127/2)=75