Question
A boy’s age is 125% of what it was 8 years ago, but
75% of what it will be after 8 years. What is his present age?Solution
Let the present age of boy be ‘x’ years. 125% of age of boy 8 years before = 75% of age of boy after 8 years => (125/100) × (x - 8) = (75/100) × (x + 8) => 125(x - 8) = 75(x + 8) => 125x - 1000 = 75x + 600 => 50x = 1600 => x = 32 yrs
A bag contains 20 white and some black balls. If the probability of drawing a black ball from the bag is 1.3 times that of drawing a white ball, ...
A bag contains 4 black balls, 6 white balls and 5 red balls. Two balls are drawn simultaneously. Find the probability that both the balls are of same c...
A bag contains 3 blue, 2 green, and 5 black pens. If five pens are selected randomly, what is the probability that exactly two are green and three are b...
The probability of selecting a rotten apple randomly from a heap of 250 apples is 0.20. What is the number of rotten apples in the heap?
...Two dice rolled. Probability that the sum is 8?
Two dice are thrown simultaneously. Find the probability that sum of the numbers appeared on both the dice is at least 7.
Out of 36 balls in a bag, some are black and the rest are white in the ratio 7:5. Two balls are drawn randomly without putting back the first one. What ...
In a bag contains 4 one rupees coins and 3 five rupees coin. If two coins are drawn at random, find the probability of getting a one rupee coin and a fi...
- A bag contains 32 balls of two different colours violet and green in the ratio of 5:3 respectively. Two balls are randomly drawn without replacement from t...
10 rotten bananas are accidentally mixed with 140 good ones. It is not possible to just look at a banana and tell whether or not it is rotten. One banan...