student

This topic has expert replies
Source: — Problem Solving |

User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pm
Location: Arabian Sea
Thanked: 125 times
Followed by:2 members

by ajith » Wed Apr 21, 2010 2:06 am
gmatmachoman wrote:A student got marks in the ratio 6:7:8:9:10 in five subjects having equal maximum marks. In all, he scored 60% marks. In how many subjects, he got more than 50% ?

1) 4 2) 5 3) 3 4) None of these
say he got 6x,7x,8x,9x and 10x marks out of y

average = 40/5x = 8x
8x is 60%
8/6x is 10%
40/6x is 50%

6.67x is 50%

he got more than 50% in 4 subjects!
Always borrow money from a pessimist, he doesn't expect to be paid back.

Legendary Member
Posts: 576
Joined: Sat Mar 13, 2010 8:31 pm
Thanked: 97 times
Followed by:1 members

by liferocks » Wed Apr 21, 2010 2:09 am
let each subject has max 100 marks and common ratio of the obtained marks is x
40x=300
x=30/4 or 15/2
so 50 =50*2/15x or 20/3x
only 6x is less than 20/3x hence he got more than 50% in 4 subjects
option 1