Can I get some assistance on this astronomy question?

[indian dj]

1) Rank the following main sequence stars in terms of increasing mass
a. A,B,F,G,O
b. G,A,O,B,F
c. O,B,A,G,F
d. G,F,A,B,O
e. O,B,A,F,G

2) You examine the H-R diagram of two star clusters (X and Y) and discover that the brightest main sequence star in cluster X is intrinsically four times brighter than in cluster Y. You may conclude that:
a. Cluster X is twice as far as cluster Y
b. Cluster Y is twice as far as cluster X
c. Cluster distances are required in order to figure out which star is intrinsically the brightest
d. Cluster X is younger than cluster Y
e. Cluster Y is younger than cluster X
f. c and d

3) Two main sequence stars (X and Y) of the same spectral type are observed to differ in apparent brightness by a factor of 100. If Y is brighter than X, you may conclude that (5 points)
a. X is twice as far as Y
b. Y is twice as far as X
c. X is younger than Y
d. Y is younger than X
e. X is ten times farther than Y
f. X is one hundred times farther than Y