A box contains 2 blue, 3 black and 5 orange balls. In how many ways can 3 balls be drawn from the box, if at least 1 black ball is to be included in the draw?
We may have (1 black and 2 non black) or (2 black and 1 non black) or (3 black). Required number of ways = (3C1×7C2) + (3C2×7C1) + (3C3) => (45 + 18 + 1) = 85
Find the rate of interest if amount after 2 years on simple interest on a capital of Rs 1000 is Rs 1200.
The monthly earnings and expenses of a person are in the ratio of 8:3. The earnings increase by 40%, and the expenses decrease by...
Two numbers are less than a third number by 25% and 34% respectively. Find the percent by which the second number is less than the first.
A and B together have total of Rs.4200 out of which they donated 10% to the orphanage school. The remaining amount is to be then redistributed between t...
In an examination the percentage of students qualified with respect to the number of students appeared from school A is 75%. The number of students appe...
If the sugar price is increased by 20% by how much percent consumption should be reduced that expense remains same.
If the numerator of a fraction is increased by 16.66 % and denominator decreased by 14.28 % then, it becomes the reciprocal of itself. Find the original...
The marks scored by a boy in three subjects are in the ratio 4 : 3 : 2. Boy scored an overall aggregate of 60% in the exam. If the maximum marks in each...
The total strength of school A is 40% more than that of school B. In school A and B, out of total number of students, 25% and 40% respectively are girls...
Rahul saves Rs. 6800 more if he spends 70% of his income instead of 90%. Find the savings of Sumit whose income is 25% more than that of Rahul, and spen...
