Question
A rectangular piece of copper foil of length 28 cm and
area 1232 cm2 is folded along its width to form a cylinder such that there is only one layer of copper foil on any part of the cylinder. What is the volume (in cm3) of the cylinder so formed?Solution
Width of the rectangular piece of copper foil = 1232/28 = 44 cm Since the foil is folded along its width to form a cylinder without any double layer, circumference of the cylinder formed = width of the rectangular foil Also, height of the cylinder so formed = length of the rectangular copper foil So, 2 × π × radius = 44 Radius of cylinder = 44 ÷ (2 × 22/7) = (44/44) × 7 = 7 cm So, volume of the cylinder so formed = π × (radius)2 × height = (22/7) × 7 × 7 × 28 = 4312 cm³
If a + b + c = 12 and ab + bc + ca = 47, and a, b, c are real numbers, find the value of a³ + b³ + c³ − 3abc.
If a + `1/b` = 1 and b + `1/c` =1 , then the value of c + `1/a` is
A sum of Rs. 25,000 is invested in SIP 'G' which offers 7% p.a. simple interest for 7 years. The interest received from SIP 'G' is invested in SIP 'H' w...
If
= 2 then find In a best-of-two chess match between Player X and Player Y, the probability that Player X wins a game is (5/9), and the probability that Player Y loses ...
If 10x2 – 6xy+y² – 4x+4= 0, then find the value of (3x+2y).
If x 2  – 15x + 51 = 0, then determine the value of (x – 5) + {1/(x – 5)}.
For a =-4 and b = 5, value of a² – b² is:
Relevant for Exams:
