Suppose P is the initial amount (which is lent, deposited, invested or principal), t is the time or tenure & r is rate of interest, then:

Step 1:

Look for brackets and complete the calculations inside them, according bracket order:
FIRST ( )   SECOND [ ]    THIRD { }

Step 2:

Look for any kind of roots (square roots, cube roots and others), indices (square of a number, cube of a number and others), exponents and powers.

Step 3:

Look for any kind of division and solve the calculations.

Step 4:

Look for any kind of multiplications and solve the calculations.

Step 5:

Look for any kind of additions and solve the calculations.

Step 6:

Look for any kind of subtractions and solve the calculations.

Downstream:

Boat is moving along the direction of water.

Suppose, u is the speed of boat in still water & v is the speed of stream, then:

Downstream Speed (y) = u + v

Speed Of Stream:

0.5(y-x)