(b) Number of questions for team A = 300
Also, number of questions for team B = 90% of 300
=
= 270
Now, let the questions attempted per hour by A = x
Then, questions attempted per hour by B = x + 7
By using the conditionof given in question,
+3= + 6
= + 3
= 270 (x + 7) = (300 + 3x+ 21)x
270x + 1890 = 321x + 3
x2 x2 + 51x - 1890 = 0
x2 + 17x - 630 = 0
x2 + 35x - 18x - 630 = 0
x(x + 35) - 18 (x + 35)= 0
(x - 18) (x + 35) = 0
⇒ x = 18, -35
So, team A attempted 18 questions per h.
(∵ Negative value of x is not permitted)