A gang of workers normally consists of 30 highly skilled, 15 skilled, and 10 semi-skilled. They are paid standard hourly rates as under: In a normal working week of 40 hours, the gang is expected to...

A gang of workers normally consists of 30 highly skilled, 15 skilled, and 10 semi-skilled. They are paid standard hourly rates as under:

In a normal working week of 40 hours, the gang is expected to produce 2,000 units of output. During the week ended December 31, the gang consisted of 40 highly skilled, 10 skilled, and 5 semiskilled. The actual wages paid were at the rate of `70, `65 and `30, respectively. Four hours were lost due to abnormal idle time and 1,600 units were produced. Calculate: (i) Wage variance; (ii) Wage rate variance; (iii) Labour efficiency variance; (iv) Gang composition variance (labour mix variance); and (v) Labour idle time variance.