A 1 km long train is travelling at 30km/h. If the train enters a tunnel that is 1 km long, how much time will it take for the train to clear the tunnel?

240 seconds OR 4 minutes

Step-by-step explanation:

Length of the train = 1 km

Length of the tunnel = 1 km

Therefore, length of the train + length of the tunnel = (1 + 1) km = 2 km

= 2000 m

Speed of the train = 30 km/hr = 8.333 metres per second

Therefore, time taken by the train to cross the tunnel = 2000 m/ 8.333 m/sec.

= 240 seconds = 4 minutes

(x3 + 6x2 + 2x - 6) • (x - 1)

step-by-step explanation:

polynomial long division :

3.2     polynomial long division

dividing :   x4+5x3-4x2-8x+6

                              ("dividend")

by         :     x-1     ("divisor")

dividend     x4   +   5x3   -   4x2   -   8x   +   6

- divisor   * x3     x4   -   x3            

remainder         6x3   -   4x2   -   8x   +   6

- divisor   * 6x2         6x3   -   6x2        

remainder             2x2   -   8x   +   6

- divisor   * 2x1             2x2   -   2x    

remainder               -   6x   +   6

- divisor   * -6x0               -   6x   +   6

remainder                     0

quotient :   x3+6x2+2x-6   remainder:   0