The H.C.F of the expressions x² - 3x² - 4 and x² - 4x² + x  is

(1) x-1

(2) x+1

(3) x²-1

(4) x² -3

If radices of a circle is doubled in length, what would be the change, in the area of the circle 7

1)  Increase 8 times

2)  Increase 4 times

3)  Increase 2 times

4)  No change

 If a man can swim downstream at 6 kmph and upstream at 2 kmph, his speed in still water is :

1) 4 km/hr

3) 3 km/hr

2) 2 km/hr

4)'2.5 km/hr