1.

At t minutes past 2 pm, the time needed to 3 pm is 3 minutes less than t2/4. Find t.

Answer»

60 – t = t2/4 – 3

⇒ t2 – 12 = 240 – 4t

⇒ t2 + 4t – 252 = 0

⇒ t2 + 18t – 14t – 252 = 0

⇒ t(t + 18) – 14(t + 18) = 0

⇒ (t + 18) (t – 14) = 0

t = 14 or t = -18 is not possible.



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