Question

At 't' minutes past two p.m. the time needed by the minutes and of a clock to show 3pm.was found to be 3minutes less than t²/4 minute find t.?​

Answer 1

solution:-

The minute hand is at t

Time needed by minute hand to show 3PM = 60 -t

According to the question ---

=> 60 - t = t^2/4 - 3

=> 60 - t =( t^2 - 12)/4

=> 4(60 - t) = t^2 - 12

=> 240 - 4t = t^2 - 12

=> - 4t = t^2 - 12 - 240

=> t^2 +4t - 252 = 0

=> D = b^2 - 4ac = 4^2 - 4*1*(-252)

= 16 +1008

= 1024

Now , -b +/- √D/2a

= -4 +/- 1024/ 2

there will be two roots

= -4 +1024/2 and -4 - 1024/2

= 14 and - 18

but time cannot be negative.

So t = 14

( attachment also)

I hope it helps you....