Need help on the above q.

Need help on the above q

Q1.The particpants of the quiz are divided equally into 2 groups.

in the first group, there are 20 more boys than girls.

in the second group, there are 12 more girls than boys.

45% of all participants are girls.

How many participants are boys?

q2. Suyin baked some pies. She gave 1/5 of them to her relatives and 30 of them to her friends. She was left with 2/3 of the pies. She packed these into 18 boxes . Some boxes contained 6 pies while the rest contained 12.

a) how many pies weee packed into 18 boxes?

b) how many boxes contained 6 pies?

Source: PSLE 2012 Maths