82) There are two families A and B. In family A, there are 4 men, 6 women and 2 children and in family B, there are 2 men, 2 women and 4 children. The recommended daily requirement for calories is.

Men 2,400, women 1,900, children 1,800 and for protein is.., Men 55 gm., women 45 gm., children 33 gm.

Calculate the total requirements of calories and proteins for each of the two families using matrix method.

83) In a certain city, there are 5 Colleges and 120 Schools. Each school has 3 peons, 1 clerk and 1 head clerk, whereas College has 5 peons, 3 clerks, 1 head clerk and an additional staff as a caretaker. The monthly salary of each of them is as follows.

Peon = Rs. 1,100

Clerk = Rs. 1,700

Head Clerk = Rs. 3,000

Caretaker = Rs. 2,500

Using matrix method, find the total monthly salary bill of each School and College.

84) Three firms A, B and C supplied 40, 35 and 25 truck loads of stones and 10, 5, 8 truck loads of sand respectively to a contractor. If the cost of stone and sand are Rs. 1,200 and Rs. 500 per truck load respectively, find the total amount paid by the contractor to each of these firms, by using matrix method.

86) There are two families X and Y. Family X has 2 men, 3 women and one child, while family Y has one man, and two children. Their individual daily requirements are as follows.

Man: 2,400 calories and 55 gms. Protein, Woman: 1,900 calories and 45 gms protein, Child 1,800 calories and 33 gms protein.

Present the above information in the form of matrices. Using matrix multiplication, calculate the total daily requirements of calories and protein for each of the two families.

87) A student has 4 places where he can have his lunch. The College Canteen charges Rs. 9 for a cold drink, Rs. 6 for a cutlet and Rs. 5 for a sandwich. The Coffee House charges Rs. 10, Rs. 8 and Rs. 9 for the same items, while fast food joint charges Rs. 12, Rs.15, Rs. 15, and the Restaurant charges Rs. 15, Rs. 25 and Rs. 20 for the above items respectively. The student wants to have one cold drink, two cutlets and one sandwich. Where should he have his lunch so that the lunch costs him the least?