CTS Company Numerical Ability Number System

Two distinct no s are taken from 1,2,3,4......28 Find the probability that their sum is less than 13

Read Solution (Total 1)

There are 28C2*2! = 378 pairs of numbers that are possible.

The pairs that sum to less than 13 are

1 + 2
1 + 3
...
1 + 11 (10)
We skip 2 + 1, because it's the same as 1 + 2
2 + 3
..
2 + 10 (8)
3 + 4
..
3 + 9 (6)
4 + 5
..
4 + 8 (4)
5 + 6
5 + 7 (2)

For a total of 30 pairs.

30/378
11 years agoHelpfull: Yes(2) No(3)

CTS Other Question

If the vertices of the triangle are A(1,2), B(-2,-3) and C(2,3) then which is the largest angle?
A. Angle(ABC)
B.Angle(BAC)
C.Angle(ACB)
D.None In 400m race A gives B a start of 7 sec and beats him by 24 sec. In another race A beats B by 10 sec.the speeds are in the ratio

a)8:7
b)7:6
c)10:8
d)6:8
e)12:10