Can you solve this 'Double if' math question?
Alan and Bala has some money.
If Alan spends $45 each day and Bala spends $15 each day, Alan will have $120 left by the time Bala spends all his money.
If Bala spends $45 each day and Alan spends $15 each day, Alan will have $840 by the time Bala spends all his money.
How much money does Alan have?
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ReplyDeleteA :B A : B 120+3u=1000+1p 8p=880
ReplyDelete1000+1p: 3p 1u=3p 1p=110
-1p l -3p l 120+9p=1000+1p 9p=990
V V 9p=880+1p 1000+990=1990
---------------------------
1000 : 0
120+3u :1u
-3u l -1u l
V V
-----------------------
120 : 0
V
Answer is $1990
ReplyDeleteNice try Sven. You used 'units and parts strategy. You are partially correct. The answer however, is incorrect.
ReplyDeleteIt is not easy to understand 'units and parts' concept too.
Anyone else care to try?
I can't solve the question.
ReplyDelete-Adree
1unit is 15. The no. of days in he first if is X and for the second if it is Y.
ReplyDelete1st if: A= 3u*X+120 B=1u*X
2nd: A=1u*Y+1000 B=3u*Y
From this we can see that X=3Y
1st:A=3u*3Y+120
2nd:A=1u*Y+1000
1000-120=880
880=2u*2Y
440=1u*Y
1000+1000=1320=A
i mean 1000+440=1440=A
ReplyDeleteI have made changes to the question stem as there was a mistake as highlighted by Jie Ren. The $1000 has been replaced by $840. Thanks Jie Ren.
ReplyDeleteActually I got 1110 leh.Just when I work backwad the unknown day a lot decimal so I thought is wrong
ReplyDeleteso I deleted the coment
ReplyDeleteNoted Eileen. My mistake then.
ReplyDelete