Question

Answer the following question​

Answer 1

Explanation:

1) Total = 30 students

Girls : Boys = 2 : 1

Total part = 2 + 1 = 3

Fraction of girls = 2/3

`Number \ of \ girls = (2)/(3)*30 = 2*10 = 20\\\\\\Number \ of \ boys = 30 - 20 = 10`

Answer: 20 girls and 10 boys

2) Total pens = 24

Red :Blue : Black = 3 : 4 : 1

Total parts = 3 + 4 + 1 = 8

`Number \ of \ red \ pens = (3)/(8)*24=3*3 = 9\\\\\\Number \ of \ blue \ pens = (4)/(8)*24=4*3=12\\\\\\Number \ of \ black \ pens = (1)/(8)*24=1*3=3`

Answer: 9 red pens

12 blue pens

3 black pens

3) Total people = 180

Adults : boys : girls = 3 : 2 : 7

Total parts = 3 + 2 + 7 = 12

`Number \ of \ adults = (3)/(12)*180=3*15=45\\\\\\Number \ of \ boys = (2)/(12)*180=2*15=30\\\\\\Number \ of \ girls = (7)/(12)*180=7*15=105\\\\`

Answer: 45 adults ; 30 boys and 105 girls

4)Total vehicles = 12000

Cars : trucks : motorcycles = 13 : 8 : 3

`Number \ of \ cars = (13)/(24)*12000=13 *500 = 6500\\`

6500 cars drove through on that day

`b) Number \ of \ trucks = (8)/(24)*1200 = 8*500 = 4000`

4000 trucks