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 Shiela purchased 11 books for Rs.10 and sold -10 books for Rs. 11, the percentage of profit is :

(1) 21%

(2) 100%

(3) 10%

(4) 11%

An article sold at Rs. 425 earned profit equal to the loss incurred when sold for Rs. 375. What is the eost price of that ar­ticle?   

1)  Rs. 370

2)  Rs. 385

3)  Rs. 390 .

4)  Rs. 400