The ratio of the number of red balls , to yellow balls , to green balls in an urn is 2 : 3 : 4 . What is the probability that a ball chosen at random from the urn is a red ball ?
2/7
510
5/9
২/৯
None of them
Find the number of zeroes in 10 x 20 x 30x……x 1000.
The total number obtained by a student in Physics, Chemistry and Mathematics together is 120 more than the marks obtained by him in Chemistry. What is the average mark obtained by him in Physics and Mathematics together?