Problem 1:
Because Leon uses 300g of mixture, the number of ml of water needs is: 30*3 = 90 ( ml )
So Leon needs 90ml more water.
Problem 2:
Total number of bananas Jacob has: 3*60 = 180 ( bananas )
Number of bananas he gave to the class: 180 - 28 = 152 ( bananas )
So Jacob has 152 bananas left.
Problem 3:
Total amount for both two and three games: 2*3*75 = 450 ( c )
So they spend a total of 450 coins.
Problem 4:
Exchange: 5 dollars= 500 c
Number of pineapples they can buy for $5 : 500/17 = 29,4
So they can buy about 29 pineapples.
Problem 5:
Total cost for adult and child tickets:
5*1.20=6$
20*50=1000 (c)=10$
6+10=16 $
So the total cost is $16.
Problem 6:
The number of blue cars is half the number of white cars: 16/2 = 8 ( blue cars )
The number of black cars is three times the number of blue cars: 8*3=24 ( black cars )
So there were 24 black cars that passed during the traffic survey.