In November's Math Meet, the Little Monsters of Beast Academy solved 1/3 of the problems. In March's Math Meet, they solved 2/7 of the problems. (There might be different numbers of problems asked in November and March.)
In total, the Little Monsters solved 15 of 28 problems over both Math Meets. How many problems were asked at March's Math Meet?
Name the total amount of problems in the November math meet x
Name the total amount of problems in the March math meet y
Now according to the information: we get the following equations:
\(x+y=28\)
\(\frac{1}{3}x + \frac{2}{7}y = 15\)
2 variables, 2 equations, we can solve for x and y, but we just need y, so
substitue \(x\) for \(28 - y\) into the 2nd equation we get
\(\frac{28-y}{3} + \frac{2y}{7}= 15\)
then we simplify to get
\(\frac{196-7y}{21} + \frac{6y}{21} = 15\)
which is
\(\frac{196-y}{21} = 15\)
multiply both sides by 21, we get
\(196 - y = 315\)
so simplify to get
\(y = -119\)
wait a sec, that can't be right, can someone fix what i did wrong? hmm....