For the first order reaction, X→Y the time taken for 96.875% completion of the reaction is 1000 minutes. Time taken for 87.5% completion of the reaction will be ------ minutes

t96.875%t50%=2.303K log 100100-96.8752.303K log 100100-50; t96.875%t50%=5 log 2 log 2 t96.875%=5t50%; Conclusion :       t99.9%=10t50%;        t75%=2t50%;     t87.5%=3t50%;   t93.75%=4t50%; t 96.875%=5t50%;