Average weight = [(a + b + c + (a+b) + (b+c) + (c+a)+(a+b+c)] / 7 = 4 (a+b+c) /7 = 4 x 175/7 = 100 kgs
3 friends A, B, C went for week end party to McDonald's restaurant and there they measure there weights in some order In 7 rounds. A, B, C, AB, BC, AC, ABC. Final round measure is 175kg then find the average weight of all the 7 rounds?
Options:
(A) 100 kgs
(B) 88.5 kgs
(C) 86.5 kgs
(D) 67.5 kgs
(E) 88.2 kgs
(A)

1/6 1/15 = 1/10
B can do the work in 10 days
A and B together can do a work in 6 days. If A alone can do it in 15 days. In how many days can B alone do it?
Options:
(A) 7
(B) 13
(C) 19
(D) 10
(E) None
(D)

N ends in the digit 1 because when N is divided by 10, the remainder is 1. Since N ends in 1, the remainder G when N is divided by 30 also ends in a 1. 11 is the only choice which ends in a 1.
When N is divided by 10 the remainder is 1 and when N is divided by 3 the remainder is 2. What is the remainder G when N is divided by 30?
Options:
(A) (a) 4
(B) (b) 7
(C) (c) 11
(D) (d) 13
(E) (e) 17
(C)