Answer:
1) 16 boys
28 girls
ratio of boys to girls =
16:28
Divide through by 4
16/4:28/4 = 4:7
ratio of boys to girls = 4:7
ratio of total to girls
total = 16 + 28 = 44
total to girls = 44:28
divide through by 4
44/4:28/4 = 11:7
ratio of total to girls = 11:7
2) Total mixture = 45 liters
ratio of sugar solution to salt solution = 1:2
Amount of sugar solution =
1/(1 +2) × 45
= 1/3 × 45 = 15 liters
3) Harry, Jerry and Jane = 1:2:5
Let Harry = H
Jerry = Je
Jane = Ja
Total number of chocolate = T
H = Ja - 8
H = 1/8 × T = T/8
Je = 2/8 × T = 2T/8 = T/4
Ja = 5/8 × T = 5T/8
Substitute (H = T/8) and (Ja = 5T/8) in the expression (H = Ja - 8)
H = Ja - 8
T/8 = 5T/8 - 8
T/8 - 5T/8 = -8
-4T/8 = -8
-T/2 = -8
-T = -8 × 2
-T = -16
T = 16
Total number of chocolates = 16
Harry's share = 1/8 × 16 = 16/8 = 2 chocolates
Jerry's share = 2/8 × 16 = 32/8 = 4 chocolates
Jane's share = 5/8 × 16 = 80/8 = 10 chocolates
Jerry's chocolate = 4