Page 41 - Arithmetic

Explanation:
1. Rejection rate = 0.05%
No. of bulbs rejected = 3
No. of bulbs rejected = 0.05% of total number of bulbs
3 = 0.05 × Total number of bulbs 100
3 = 5 × Total number of bulbs 10000
Total number of bulbs = 3×10000 5
Total number of bulbs = 6,000
2. Let the amount of money with Sam be x
Money Sam gave to his wife = 40% of x = 0.40x
Amount left with Sam = x – 0.40x = 0.60x
Amount Sam gave to his two daughters = 2 × 20% of 0.60x = 0.24x Amount left with Sam = 0.60x – 0.24x = 0.36x
Money spent on his medical expenses = 50% of 0.36x = 0.18x Amount left with Sam = 0.36x – 0.18x = 0.18x
Amount left with Sam = $18,000
18000 = 0.18x
x = $100,000
3. Amountofsugarin25lbsofsugar= 4 ×25=1lbs 100
Add x lbs of sugar to the solution 1+𝑥 = 10
25+𝑥 100
100 (1 + x) = 10 (25 + x) 10 (1 + x) = 25 + x
10 + 10x = 25 + x
9x = 15
x = 15 = 5 or 12 933
4. Liters of acid in 8 liters of 25% solution = 25 × 8 = 2 liters 100
5. No. of blue balls = 800
% of blue balls taken out = 20% of 800 = 20 × 800 = 160
100
No. of black balls = 200
% of black balls taken out = 15% of 200 = 15
100
Total number of balls = 200 + 800 = 1000 Number of balls removed = 160 + 30 = 190
% of balls removed = = 190 × 100 = 19% 1000
× 200 = 30
Page 40 of 55
Arithmetic Concept