Question
The ratio of volumes of spheres A and B is 8:27. If the
difference between their total surface area is 3080 cm² then find diameter of sphere A. (in cm)Solution
ATQ,
Volume ratio A:B = 8:27 → radii ratio = 2x : 3x Surface area of A = 4π(2x)² = 16πx² Surface area of B = 4π(3x)² = 36πx² Difference = 36πx² – 16πx² = 20πx² = 3080 Solve: 20πx² = 3080 x² = 3080 / (20 × 3.1416) ≈ 49 x = 7 Radius of A = 2x = 14 Diameter = 2 × radius = 28 cm
which of the following pairs of non-zeroes values of p and q make the 6-digit number 674pq0 divisible by both 3 and 11?
Find the least 4-digit number which is when divided by 16, 20, and 24 leaves a remainder of 9 in each case.
Find the least 4-digit number which is when divided by 21, 28, and 36 leaves a remainder of 11 in each case.
When a number is divided by 119, the remainder remains 15. When the same number is divided by 17, what will be the remainder?
 If a nine-digit number 89563x87y is divisible by 72, then the value of √ (8x -6y) will be ∶
x + 5x – 2x – 24 has a zero at x = 6. Find the other zeros.
If ‘48b297a54’ is a nine digit number which is divisible by ‘11’, then find the smallest value of (a + b).
What is the number of divisors of 480?
Which of the following numbers is divisible by 11?
How many divisors does the number 5040 have?
Relevant for Exams:
