Seven positive integers have an arithmetic average of 34 and a median of 42. If the greatest of these integers is 7 more than 2 times the least of the integers, what is the maximum possible value of the greatest integer?
(A) 42
(B) 49
(C) 70
(D) 52
(E) 91
the answer by
amanvermagmat is great way to do the question and saves time,
I solved it in more conventional way,
let the seven numbers in increasing order be a,b,c,d,e,f,h
given that median is 42, so d = 42
largest no. is seven more than two times the smallest, h = 2a+7
Average of seven no.s is given as 34,
a + b + c + 42 + e + f + 2a+7 = 238
we need to maximise 2a+7, so we have to minimise all other terms
the question does not mention that numbers are distinct so we can repeat the numbers,
so lowest value for b and c is a (the smallest number itself)
also the lowest value for e and f will be at least 42. (equal to the median)
plugging it all in,
a + a + a + 42 + 42 + 42 + (2a+7) = 238
a = 21
So the largest no is (21 x 2) + 7 = 49