Search found 2 matches


x can do work by 12 hours
y and z together can do the work by 15.18 / (15+18)

x : y+z = 12 : 15 . 18 / 33 = 2 : 15 / 11 = 22 : 15

by DeepaVarma

Sun Jan 14, 2018 11:23 pm
Forum: Problem Solving
Topic: og math # 130
Replies: 132
Views: 58257

TTT

Total 3 points' combinations = 9C3

nCr = n! / ((n-r)! . r!)

9C3 = 9! / 6!.3! = 9.8.7 / 3.2 = 84

Out of 84 combination , 8 will be straight lines

84 - 8 = 76

by DeepaVarma

Fri Jan 12, 2018 1:02 am
Forum: Problem Solving
Topic: How many triangles on the coordinate plane
Replies: 131
Views: 80066