A sells and article to B at a profit of 10%,B sells it to C for rs577.50 at a profit of 5%.How much did it cost for A?

 $500

Step-by-step explanation:

A sells to B at a profit of 10%:    1.10A = B

B sells to C for $577.50 at a profit of 5%:    1.05B = 577.50

Substitute B with 1.10A in the second equation:

1.05(1.10A) = 577.50

       1.155A = 577.50

               A = 500

$30.32

step-by-step explanation:

65.00*.12=2.80

65.00-2.80=57.20

57.20*1.06=60.632

60.632/2=30.316

12

step-by-step explanation:

12 + 5 = 17

12x2=24

24-7=17