Question

d) 5! + 4! + 2! + 1! = 147​

Answer 1

$5!+4!+2!+1!=\\\\ (5\times4\times3\times2\times1)+(4\times3\times2\times1)+(2\times1)+(1)=\\\\ 120+24+2+1=\boxed{147}$