A box containing 58 iron balls weighed 2145g . when 46 of the iron balls were removed, the mass of the box and the remaining iron balls weighed 489g. What was the mass of the box?
Solution
Number of iron balls left when 46 were removed
58 – 46 = 12 (iron balls)
Box + 58 iron balls ----- 2145 g
Box + 12 iron balls ----- 489 g
(58 – 12) iron balls ----- 2145 g – 489 g
46 iron balls ----- 1656 g
1 iron ball ----- 1656 g divided by 46 = 36 g
Box + 58 iron balls ----- 2145 g
Box + (58 x 36 g) ----- 2145 g
Box + 2088 g ----- 2145 g
Box ----- 2145 g – 2088 g = 57 g
Answer: The box was 57 g.
Saturday, March 21, 2009
Tao Nan School P5 SA2 2006 Math Q45
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4 comments:
12 is the number of balls remaining.
Reworded statement. Thanks for pointing out.
Question on weight of 58 iron balls plus box should be 2145g. Your question wrote 2154.
Amended. Thanks for highlight again.
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