Form 1 maths

NgFion

2010-10-30 3:12 pm

(1) 72 marbles are divided into two groups , 7 times the number of marbles in the smaller group is equal to 5 times that in the larger group , find the number of marbles in the smaller group .

(2) concert tickets in $400 , $200 and $100 each are available for sale. the number of $200 tickets sold is 4 times as many as that of $400 tickets . the number of $100 tickets sold is 380 more than that of $200 tickets , if the total income from the sale of tickets is $86000 how many $400 tickets are sold ?

回答 (1)

螞蟻雄兵

2010-10-30 4:21 pm

✔ 最佳答案

(1) 72marbles are divided into two groups，7 times thenumber of marbles in the smaller
group is equal to 5 times that in the larger group，findthe number of marbles in the smaller
group .
Sol
Smaller=x，larger=72－x
7*x=5*(72－x)
7x=360－5x
x=30

(2) concert tickets in $400，$200 and $100 each are availablefor sale.the number of $200
tickets sold is 4 times as many as that of $400 tickets，the number of $100 tickets sold is
380 more than that of $200 tickets，if the total incomefrom the sale of tickets is $86000
how many $400 tickets are sold ?
Sol
$400=x
the number of $200 tickets sold is 4 times as many as that of $400 tickets
=>$200=4x
the number of $100 tickets sold is 380 more than that of $200 tickets
=>$100=4x+380
total income from the sale of tickets is $86000
=>400*x+200*4x+100*(4x+380)=86000
4*x+2*4x+1*(4x+380)=860
4x+8x+4x+380=860
16x=480
x=30
$400 tickets sold=$400*30=$12000

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