Mohan and Rohan are very intelligent in mathematics. They always try to relate the concept of Maths in daily life. One day while turning back from school to home, Mohan told Rohan that his bicycle tyre is taking 350 revolutions to cover the distance from school to home because the radius of the tyre is 10.5 inches. Rohan got excited to find how many times his bicycle tyre will take revolutions to cover the same distance if the radius of his tyre is 7 inches. Find the number of revolutions for Rohan.
Option 1: 44 Option 2: 328
Option 3: 525 Option 4: 788
Answers
Answer:
Rohan is very intelligent in maths. He always try to
relate the concept of maths in daily life. One day he is
walking away from the base of a lamp post at a speed
of 1 m/s. Lamp is 4.5 m above the ground.
(i) If after 2 second, length of shadow is 1 meter,
what is the height of Rohan ?
(a) 145 cm (b) 120 cm
(c) 150 cm (d) 175 cm
(ii) What is the minimum time after which his shadow
will become larger than his original height?
(a) 1 sec (b) 2 sec
(c) 3 sec (d) 4 sec
(iii) What is the distance of Rohan from pole at this
point ?
(a) 2 m (b) 1 m
(c) 3 m (d) 4 m
(iv) What will be the length of his shadow after 4
seconds?
(a) 2 m (b) 1 m
(c) 3 m (d) 4 m
(v) Which similarity criterion is used in solving the
above problem
(a) SAS similarity criterion
(b) AA similarity criterion
(c) SSS similarity criterion
(d) none of these
GIven,
Mohan and Rohan are very intelligent in mathematics. They always try to relate the concept of Maths in daily life. One day while turning back from school to home, Mohan told Rohan that his bicycle tyre is taking 350 revolutions to cover the distance from school to home because the radius of the tyre is 10.5 inches. Rohan got excited to find how many times his bicycle tyre will take revolutions to cover the same distance if the radius of his tyre is 7 inches.
To find,
The number of revolutions for Rohan to cover the same distance from school to home.
Solution,
Radius of Mohan's tyre (R) = 10.5 inch
Circumference (one round of the tyre) = 2 π R
So, Circumference = 2 * 22 / 7 * 10.5 = 66 inch
Total number of rounds to cover the distance = 350
Total distance covered = 350 * 66
Total distance covered by Mohan = 23100 inch
The radius of Rohan's cycle = 7 inch
Circumference (one round of the tyre) = 2 π R
So, Circumference = 2 * 22 / 7 * 7 = 44 inch
Total distance to be covered = 23100 inch
Total number of revolutions required = 23100/44 = 525
Hence, the number of revolutions required for Rohan is 525 (Option 3)