There are \(5!\) ways to arrange the letters. Each permutation where E comes before I has a pair where E comes after I (namely swap E and I), so the number of permutations where E comes before I is exactly half of it, or \(5!/2 = 60\).
–
Ivan Koswara
·
3 years, 5 months ago

Log in to reply

If f is a differentiable function and f(x^2-y^2 )=xf(x)-yf(y) and f(1)=2,then find f(2).

## Comments

Sort by:

TopNewestThere are \(5!\) ways to arrange the letters. Each permutation where E comes before I has a pair where E comes after I (namely swap E and I), so the number of permutations where E comes before I is exactly half of it, or \(5!/2 = 60\). – Ivan Koswara · 3 years, 5 months ago

Log in to reply

Log in to reply

– Rama Rao · 3 years ago

If x^2015/2015+x^2014/2014+x^2013/2013+⋯+x+1=0, find the number of real roots.Log in to reply