问题1. Amina想到一个数字，并从中减去5/2。她将结果乘以8。现在获得的结果是她所想到的相同数字的3倍。号码多少?
解决方案：
Let the number be x,
According to the question,
(x – 5/2) × 8 = 3x
Solving for x,
⇒ 8x – 40/2 = 3x
⇒ 8x – 3x = 40/2 (Bring like terms together)
⇒ 5x = 20 (Divide both sides by 5)
⇒ x = 4
Thus, the number is 4.
问题2。一个正数是另一个数的5倍。如果两个数字都加上21，则新数字之一将变为另一个新数字的两倍。有多少个?
解决方案：
According to the question,
Let one of the positive number be x then other number will be 5x.
Therefore,
5x + 21 = 2(x + 21)
Solving for x,
⇒ 5x + 21 = 2x + 42
⇒ 5x – 2x = 42 – 21 (Bring like terms together)
⇒ 3x = 21 (Dividing both sides by 3)
⇒ x = 7
1st number = x = 7
2nd number = 5x = 5×7 = 35
问题3.两位数字的数字总和为9。当我们交换数字时，发现所得的新数字比原始数字大27。两位数字是什么?
解决方案：
Let the digit at tens place be x then digit at ones place will be (9 – x).
Original two-digit number = 10x + (9 – x)
After interchanging the digits, the new number = 10(9 – x) + x
According to the question,
10x + (9 – x) + 27 = 10(9 – x) + x
Solving for x,
⇒ 10x + 9 – x + 27 = 90 – 10x + x
⇒ 9x + 36 = 90 – 9x
⇒ 9x + 9x = 90 – 36 (Bring like terms together)
⇒ 18x = 54 ( Divide both sides by 18)
⇒ x = 3
Original number = 10x + (9 – x) = (10 × 3) + (9 – 3) = 30 + 6 = 36
Thus, the number is 36.
问题4.两位数的两位数之一是另一位数字的三倍。如果将这个两位数字的数字互换，然后将结果数字添加到原始数字中，则得到88。原始数字是什么?
解决方案：
Let the digit at tens place be x then digit at ones place will be 3x.
Original two-digit number = 10x + 3x
After interchanging the digits, the new number = 30x + x
According to the question,
(30x + x) + (10x + 3x) = 88
Solving for x,
⇒ 31x + 13x = 88
⇒ 44x = 88 (Divide both sides by 44)
⇒ x = 2
Original number = 10x + 3x = 13x = 13×2 = 26
问题5：Shobo母亲的现年年龄是Shobo现年的六倍。 Shobo从现在起的五岁将是他母亲现在的年龄的三分之一。他们现在的年龄是几岁?
解决方案：
Let the present age of Shobo be x then age of her mother will be 6x.
Shobo’s age after 5 years = x + 5
According to the question,
(x + 5) = (1/3) × 6x
Solving for x,
⇒ x + 5 = 2x
⇒ 2x – x = 5 (Bring like terms together)
⇒ x = 5
Present age of Shobo = x = 5 years
Present age of Shobo’s mother = 6x = 30 years.
问题6. Mahuli村有一个狭窄的矩形地块，供学校使用。情节的长度和广度之比为11：4。以每米₹100的费率，村庄panchayat需花费₹75000来围堵该地块。地块的尺寸是多少?
解决方案：
Let the length of the rectangular plot be 11x and breadth be 4x.
Rate of fencing per metre = ₹100
Total cost of fencing = ₹75000
Perimeter of the plot = 2(l+b) = 2(11x + 4x) = 2 × 15x = 30x
Total amount of fencing = (30x × 100)
According to the question,
(30x × 100) = 75000
⇒ 3000x = 75000
⇒ x = 75000/3000
⇒ x = 25
Length of the plot = 11x = 11 × 25 = 275m
Breadth of the plot = 4 × 25 = 100m.
问题7.哈桑购买了两种校服布料材料，衬衫材料每米50卢比，裤子材料每米90卢比。他每购买3米的衬衫材料就购买2米的裤子材料。他以12％和10％的利润出售材料。他的总销售额为3600卢比。他买了多少裤子材料?
解决方案：
Let 2x m of trouser material and 3x m of shirt material be bought by him
Selling price of shirt material per meter = ₹ 50 + 50 × (12/100) = ₹ 56
Selling price of trouser material per meter = ₹ 90 + 90 × (10/100) = ₹ 99
Total amount of sale = ₹36,600
According to the question,
(2x × 99) + (3x × 56) = 36600
⇒ 198x + 168x = 36600
⇒ 366x = 36600
⇒ x = 36600/366
⇒ x = 100
Total trouser material he bought = 2x = 2 × 100 = 200 m.
问题8.一群鹿在野外放牧，其余四分之三在附近玩耍。其余的9个是池塘里的饮用水。在群中找到鹿的数量。
解决方案：
Let the total number of deer be x.
Deer grazing in the field = x/2
Deer playing nearby = x/2 × ¾ = 3x/8
Deer drinking water = 9
According to the question,
x/2 + 3x/8 + 9 = x
(4x + 3x)/8 + 9 = x
⇒ 7x/8 + 9 = x
⇒ x – 7x/8 = 9
⇒ (8x – 7x)/8 = 9
⇒ x = 9 × 8
⇒ x = 72
问题9.祖父比孙女大十倍。他也比她大54岁。找到他们现在的年龄。
解决方案：
Let the age of granddaughter be x and grandfather be 10x.
Also, he is 54 years older than her.
According to the question, 10x = x + 54
⇒ 10x – x = 54
⇒ 9x = 54
⇒ x = 6
Age of grandfather = 10x = 10 × 6 = 60 years.
Age of granddaughter = x = 6 years.
问题10.阿曼的年龄是他儿子的年龄的三倍。十年前，他的年龄是儿子的五倍。找到他们现在的年龄。
解决方案：
Let the age of Aman’s son be x then age of Aman will be 3x.
According to the question,
5(x – 10) = 3x – 10
⇒ 5x – 50 = 3x – 10
⇒ 5x – 3x = -10 + 50
⇒ 2x = 40
⇒ x = 20
Aman’s son age = x = 20 years
Aman age = 3x = 3 × 20 = 60 years