Question

John's average score on three tests is 87%. What is the least he can score on his fourth test so that his average grade will be at least 90%?

Answer 1

solve
\[\frac{3\times87+x}{4}=90\] fpr x

Answer 2

\[3\times 87+x=4\times 90\]
\[261+x=360\]
\[x=360-261=99\]

Answer 3

hmm doesn't look good for john