100 students are majoring in math, business, or both. 72% of the students are business majors, and 58% are math majors. How many students are majoring in both?
If 72% are business majors, then 28% are not.
If 58% are math majors, then 42% are not.
So, 28+42 = 70% of the students, are not majoring in both.
So, 100 – 70 = 30% students are majoring in both.
The average age of a 52 members of a village is 32 yrs. If the age of the youngest member be 7 yrs., then what was the average age of the village at the birth of the youngest member?
Total ages of all members
= 52 x 32 = 1664 yrs.
7 yrs. ago, total sum of ages = 1664 – (52 x 7) = 1300 yrs.
But at that time there were 51 members in the family.
Average at that time
= 1300/51 = 25.49 yrs.
Hence option 10.(None of the above) is the correct answer.
A student gets 4 marks for each correct answer and 1 mark is deducted for a wrong answer. If he had done 80 questions at all and he has got only 240 marks, The correct answer he has attempted are?
We have a 15-litre solution containing 40% of DI water in the HCL.
=> Quantity of DI water in the solution =(15* 40)/100= 6
Now 5 litre of HCL is added to the solution.
=> Total quantity of the new solution = 15 + 5= 20
Percentage of DI water in the new solution = 6*100/20
= 600/20 = 30%
Let x be the numerator and the fraction be x / (x - 6).
By the question,
x + 8 / (x - 6 + 8) = 9 / 7
7x + 56 = 9x + 18
-2x = -38, x = 19
So, the fraction will be
19 / 13.
The number of seats in a cinema hall is increased by 25%. The cost of each ticket is increased by 10%. The effect of these changes on the revenue collection will be an increase of?
Let the number of seats initially inth cinema hall be 100 and the cost of weach ticket be ₹ 100.
Total revenue = 100 x 100 = ₹10000
In second condition,
Number of seats = 125
Cost of new tickets = ₹110
New Revenue = 110 x 125 = ₹13750
Increase in revenue collection = ₹ (13750-10000) = ₹3750
Percentage increase = (3750/10000) x 100 = 37.5%