pgbp doubt??

i have ipcc may attempt..n i dont know anything abt pgbp

suppose  thre is an expnese...in buk its written that its 60% value is allowed

so does it mean this

suppose income is 50000

expenses 10000(assumed)

(-)allowed    6000

or it shud be

50000- 6000??

and one more thing...is it like jo expense pe deduction mil chuki hain ..if we recive them later thn they r treated as income ..odrwise not??