Illustration 6. Standard hours for manufacturing two products m and n are 15 hours per unit and 20 hours per unit respectively. Both products require identical kind of labour and the standard wage rate per hour is rs. 5. In the year 2011, 10,000 units of m and 15,000 units of n were manufactured. The total of labour hours actually worked were 4,50,500 and the actual wage bill came to rs. 23,00,000. This included 12,000 hours paid for @ rs. 7 per hour and 9,400 hours paid for @ rs. 7.50 per hour, the balance having been paid at rs. 5 per hour. You are required to compute the labour variances