P,Q,R can't be 0, because their product is nonzero. Either of S and T could be 0, but the third one only works if S is 0.
Write out the problem. ...Simplify the first fraction. ...Simplify the second fraction. ...Multiply the numerators of both fractions. ...Multiply the denominators of both fractions. ...Place the new numerator over the new denominator.
Answer:9400 backpacks
Step-by-step explanation
since the number of packs to be sold in a is represented by x,
selling price for 1 week = 35x
cost price for 1 week = 15x
profit = 35x-15x = 20x
additional cost of production = 11,000
this implies that 20x - 11,000
7800
20x - 11,000
7,800
20x
7800+ 11000
20x
18,800
x
18800/2
x
9,400
at least 9,400 packs have to be sold each week to make a profit of $7800
15 is 30% of
50 Change the percentage to a decimal by dividing it over 100:

Divide 15 over 0.3:
False, 20 is not a factor of 24