Alex has a pile of money worth $82.40. he has dimes, quarters, and $5 bills. the number of quarters is twice the number of dimes, and the number of $5 bills is the same as twice the number of quarters. how many dimes does alex have?

4 dimes

Step-by-step explanation: I just did guess and check. FIrst i multiplied different numbers by 5. 5x16= 80, which is close to 82.4 so there might be 16 5$ bills. Half of 16 is 8, so there would be 8 quarters, the number of quarters (8) is twice the number of dimes, 8/2= 4. So there would be 4 dimes. To double check, 4 dimes is 40 cents, plus 8 quarters which is 2 dollars (.25x8=2) And finally 16,  5 dollar bills is 80 dollars (16x5=80) To add it all up 80+2+.40= 82.40

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: