In a lottery there were 90 tickets numbered 1 to 90. Five tickets were drawn at random. The probability that two of the tickets drawn numbers 15 and 89 is

Options

A. `2//801`
B. `2//263`
C. `1//267`
D. `1//623`

Answer

A

Explanation

Out of 90 tickets, two tickets already considered of selecting 5 tickets. We have to select only 3 tickets out of 88 tickets.
` rArr ` Required probability = ` ( ""^(88)C _ 3 )/ ( ""^(90)C_ 5 ) `
` ((88 xx 87 xx86 ) /( 3 xx 2 xx 1 ))/( ( 90 xx 89 xx 88 xx87 xx86 )/( 5 xx 4 xx 3 xx 2 xx 1)) `
` = ( 5 xx 4 )/ ( 90 xx 89 ) = ( 2 ) /( 801 ) `