Mrs Tan packed a total of 1078 calculators and board games into 49 boxes. The calculators and board games were packed in separate boxes. Each box could hold either 28 calculators or 7 board games only.
How many board games were there in all?
Source: Rosyth
Nebbermind
No. of boxes for calculators = U
No. of boxes for games = 49 – U
(28 x U) + 7x (49 – U) = 1078
=> 21U = 1078 – 343
U = 35
No. Of boxes of games = 49 – 35 =14
No. Of board games = 14 x 7 = 98
laughingcat
Thank you Nebbermind…….this is interesting. Didn’t know can use algebra method.
BigDevil
Use Assumption method.
Assume all 49 boxes contained board games.
49 × 7 = 343
Short of : 1078 – 343 = 735 to be made up by calculators
28 – 7 = 21
735 ÷ 21 = 35 (boxes with calculators)
Number of boxes of board games -> 49 – 35 = 14
Number of board games -> 14 × 7 = 98
laughingcat
Thank you BigDevil. Didn’t know can use assumption method. Got it!
BigDevil
You are welcome!
You can always rephrase the question into the more familiar…
49 animals on a farm with a total of 1078 legs.
Animal A has 7 legs, while Animal B has 28 legs.
How many legs belong to Animal A are there? 😛
laughingcat
Ah! Nice!
49 x 7 = 343 (assuming all 49 boxes are each packed with 7 board games)
1078 – 343 = 735
28 – 7 = 21 (difference)
735/21 = 35 (boxes packed with calculators)
(49 – 35) x 7 = 98
Ans : 98 board games.
laughingcat
Thank you alfretztay. Didn’t know can use assumption method.
You are welcome, laughingcat. 🙂
