Question
A cyclist has to cover 180 km. She rides the first 20%
at 25 kmph, half of the distance at 30 kmph, and the remainder at 20 kmph. What is her approximate average speed?Solution
ATQ, Time for the first segment at 25 kmph = (180 × 0.20) / 25 = 1.44 hours Time for the second segment at 30 kmph = (180 × 1/2) / 30 = 3 hours Distance for the third segment = 180 - (180 × 0.20) - (180 × 1/2) = 180 - 36 - 90 = 54 km Time for the third segment at 20 kmph = 54 / 20 = 2.7 hours Average speed = 180 / (1.44 + 3 + 2.7) ≈ 32.73 kmph
A person borrows ₹5000 at 12% per annum simple interest. He repays ₹3200 at the end of 2 years. How much does he still owe after 2 years?
- A discount of 20% was offered on a product. If the product was marked 75% above the cost price, find the profit percentage.
What is the primary purpose of an operating system in a computer system?
In a right triangle, the sides are in the ratio 3:4:5. A circle is inscribed in the triangle. What is the area of the triangle covered by the circle?Â
If cos A = 4/5 and A is an acute angle, find the value of 3 tan A + 4 sec A.
A and B invested ₹50,000 and ₹75,000, respectively, in a business. After 6 months, A withdrew ₹10,000, and B added ₹25,000. At the end of the ye...
The derivative of y = eË£ · cos(x) isÂ
Find the distance between points A(2, 3) and B(7, 8).
If the homogeneous system of equations
x + y + z = 0
2x + 3y + 4z = 0
has a non-trivial solution, then the value of k is:
3x + 5y + kz = 0
