請寫題解Let y be...
1. In a school, 5/7 of the students passed a Mathematics test. If 160 students passed the test, find the total number of students who sat for the test.
2. Sam pays $110 for 2 boxes of ice cream and 4 packs of soft drink in a supermarket. If the price of each pack of soft drink is one-third of each box of ice cream, find the price of
(a) a box of ice cream,
(b) 3 boxes of ice cream and 5 packs of soft drink.
2006-11-23 15:13:23 · 4 個解答 · 發問者 ? 7 in 科學 ➔ 數學
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1 let x be the total number of students who sat for the test
(5/7)x=160
5x=1120
x=224
the total number of students who sat for the test is 224
2a let x be the price of a box of ice cream
let x/3 be the price of a pack of soft drink
2x+4(x/3)=110
6x+4x=330
10x=330
x=33
the price of a box of ice cream is $33
x/3=11
the price of a pack of soft drink =$11
b the price of 3 boxes of ice cream and 5 packs of soft drink.
=3(33)+5(11)
=99+55
=154
the price of 3 boxes of ice cream and 5 packs of soft drink. is $154
2006-11-23 15:21:58 · answer #1 · answered by Amby 6 · 0⤊ 0⤋
1.let x be the number of students who sat for the test
5/7x=160
x=160(7/5)
x=32(7)
x=224
2a. let x be the price of ice cream
2x+x/3(4)=110
3【2x+x/3(4)】=(110)3
6x+4x=330
10x=330
x=33
2b. one box of ice cream$33
one pack of soft drink$【110-$33(2)】/4=$11
33(3)+$11(5)
=99+55
=$154
2006-11-25 06:05:52 · answer #2 · answered by chiu yee 1 · 0⤊ 0⤋
1.
Let y be the total number of students who sat for the test
5/7n=160
5/7n(7)=160(7)
5n=1120
5n/5=1120/5
n=224
the total number of students who sat for the test is 224.
2.
Let y be the price of each pack of soft drink
2(3y)+4y=110
10y=110
10y/10=110/10
y=11
The price of each pack of soft drink is $11
(a) a box of ice cream is 11(3)= $33
(b)33(3)+11(5)
=99+55
=154
3 boxes of ice cream and 5 packs of soft drink is $154
2006-11-23 15:33:31 · answer #3 · answered by HUNG 2 · 0⤊ 0⤋
1. let y be the number of students who sat for test:
5/7 y=160
y=160 x 7/5
y=224
Therefore,the number of students who sat for test is 224.
2.(a)let y be the price of a box of ice cream,1/3 y be the price of a pack of soft drink:
2y+(4)(1/3y)=110
2y+4/3y=110
10/3y=110
y=110 x 3/10
y=33
Therefore,the price of a box of ice cream is 33.
2.(b)let y be the price of a box of ice cream,1/3 y be the price of a pack of soft drink:
Since refer to 2.(a),y=33
Therefore,1/3 x 33=11
The price of 3 boxes of ice cream and 5packs of soft drink:
3 x 33 + 5 x 11
=99+55
=154
2006-11-23 15:32:48 · answer #4 · answered by 天藍 1 · 0⤊ 0⤋