A company produces a certain chemical, the standard material cost being:

40 per cent of material X at ₹20 per kg.

60 per cent of material Y at ₹30 per kg.

A standard loss of 10 per cent is expected in production. During one month, 171 kgs. of chemical was produced from the use of 90 kgs. of material X at ₹18 per kg. and 110 kgs. of material Y at ₹34 per kg. Calculate the following variances for the month: (i) materials price variance,

(ii) materials mix variance, and (iii) materials yield variance.