Answer:
12 and 2100
Explanation:
(a)
Divide 4800 by 5 for pens per hour produced by 80 machines.
4800 ÷ 5 = 960 pens per hour
Divide 960 by 80 for pens per hour produced by 1 machine.
960 ÷ 80 = 12
Thus 1 machine produces 12 pens per hour
(b)
Multiply 12 by 7 for pens produce in 7 hours by 1 machine.
12 × 7 = 84 pens per hour
Multiply 84 by 25 for pens produced in 1 hour by 25 machines.
84 × 25 = 2100
Thus 2100 pens are produced by 25 machines in 1 hour