The juice stall at the circus stocked just 2 brands of orange juice tetra packs. Brand A costs $1 per pack and brand B costs $1.5 per pack. Last week , brand A contributed to q% of stall’s revenue and accounted for r% of sales of juice tetra packs. Which of the following expresses q in terms of r? Options
A) 100r/(150 – r)
B) 200r/(250-r)
C) 200r/(300-r)
D) 250r/(400-r)
E) 300r/(500-r)
1. Let the number of units sold be 100. Then n units of A are sold and (100-n) units of B are sold.   Total revenue= Revenue due to A + Revenue due to B   = (No.of units of A sold * Cost/unit of A) + (No.of units of B sold * cost/unit of B)   = r *1 + (100-r) *1.5   = r + (150-1.5r) --- (1)   2. But we know, revenue due to A = q %. of the total revenue --- (2)   3. To express q in terms of r we need to relate (1) and (2)   4. q % = r / ( r + (150-1.5r))   or q = 100r / 150-0.5r = 200r/(300-r)   200r/(300-r)
<result>C</result>
The juice stall at the circus stocked just 2 brands of orange juice tetra packs. Brand A costs $1 per pack and brand B costs $1.5 per pack. Last week , brand A contributed to q% of stall’s revenue and accounted for r% of sales of juice tetra packs. Which of the following expresses q in terms of r?