Percentage problems Practice Question and Answer
3 Q: The cost of an article was 75. The cost was first increased by 20% and later on it was reduced by 20%. The present cost of the article is:
575 0639c91d6c7eb1b240b5fc0e7
639c91d6c7eb1b240b5fc0e7- 172true
- 260false
- 375false
- 490false
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Answer : 1. "72"
Q: The sum of weights of A and B is 80 kg. 50% of A's weight is $${5\over6}$$ times the weight of B. Find the difference between their weights.
590 064ccef6ba919c8488e304799
64ccef6ba919c8488e304799- 120 kgtrue
- 210 kgfalse
- 325 kgfalse
- 415 kgfalse
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Answer : 1. "20 kg"
Explanation :
Let's denote the weight of A as 𝑥x kg and the weight of B as 𝑦y kg.
Given:
- 𝑥+𝑦=80x+y=80 (Sum of weights of A and B is 80 kg)
- 0.5𝑥=56𝑦0.5x=65y (50% of A's weight is 5665 times the weight of B)
We can solve these two equations to find the values of 𝑥x and 𝑦y, and then calculate the difference between their weights.
From equation 2: 0.5𝑥=56𝑦0.5x=65y Multiply both sides by 2 to get rid of the fraction: 𝑥=56𝑦×2x=65y×2 𝑥=106𝑦x=610y 𝑥=53𝑦x=35y
Now substitute this expression for 𝑥x into equation 1: 53𝑦+𝑦=8035y+y=80 83𝑦=8038y=80 Multiply both sides by 3883: 𝑦=80×38y=80×83 𝑦=30y=30
Now that we have found the weight of B, we can find the weight of A using equation 1: 𝑥+30=80x+30=80 𝑥=80−30x=80−30 𝑥=50x=50
So, the weight of A is 50 kg and the weight of B is 30 kg.
Now, let's find the difference between their weights: Difference=Weight of A−Weight of BDifference=Weight of A−Weight of B Difference=50−30Difference=50−30 Difference=20Difference=20
Therefore, the difference between their weights is 20 kg.
Q:Direction: Study the following information carefully and answer the questions given below.
25% of the boys and 60% of the girls from a college participated in an event. The total number of girls in the college is equal to the number of boys, who do not participate in the event.
If the difference the number of boys and girls, who participated in the event is 40, then the total number of boys and girls in the college is
354 064e5f38ed928d8b7160e4a2a
64e5f38ed928d8b7160e4a2a25% of the boys and 60% of the girls from a college participated in an event. The total number of girls in the college is equal to the number of boys, who do not participate in the event.
- 1175false
- 2210false
- 3350false
- 4420false
- 5None of thesetrue
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