On destructive distillation, 1000 kg of coal gives P kg of coke, Q litres of ammonia, R litres of coal tar and S m3 of coal gas. The value of P, Q, R and S respectively are:
700, 400, 100, 50
When coal is subjected to destructive distillation it gives coal gas, liquor ammonia, coal tar and coke. 1000 kg of coal gives 700 kg of coke, 100 litres of ammonia, 50 litres of coal tar and 400 m3 of coal gas. Hence, the values of P, Q, R, and S respectively are 700, 100, 50, 400.