We can answer the problem using a rule of three, simple, direct proportion and also using fractions. First the rule of three:
8 apples ------> 15 min
16 apples ----> x
x = (16)(15)/8
x = 30
therefore he can eat 16 apples in 39 minutes.
We can also equate fractions like so:
8/15 = 16/y
and solve for y:
y = 15*16/8
y = 30
the same answer
0.03x+0.035 (5000-x)=155
Solve for x
X=4000 invested at 3%
5000-4000=1000 invested at 3.5%
You collected 3.90. All you have to do is multiply your amount given, .05 by the number of cans, 78. (.05*78) That should equal to 3.90, your answer.
