a) A shop sells watermelons each weighing 1 kg. The shop also sells bags of oranges. If 5 bags of oranges and 2 watermelons weigh exactly the same as 3 bags of oranges and 8 watermelons, how much does a single bag of oranges weigh? b) If 250 mL of 3% NaCl solution is mixed with 150 mL of 10% NaCl solution, what is the strength (in % NaCl by volume) of the new mixture? c) The period of a pendulum, T is given by: T= 2x 9 where, I represents the length of the pendulum and g is acceleration due to gravity. i) Make the pendulum length, 1, the subject of the equation. ii) How long must the pendulum be if the desired period, T is 1 second given g is 9.8 m/s.