Question
A race track is in the shape of a rectangle with length
of 30 metres and area of 4500 m2. A car takes 20 seconds to make one lap around the perimeter of this track. If the car and a person whose speed is 5 m/s, started moving at the same time along the perimeter of the track but in opposite directions, then find the distance between the car and the person, 3 seconds before they cross each other.Solution
Area of the track = length of track x breadth of track = 30 x breadth of track = 4500 So, breadth of track = 4500 ÷ 30 = 150 So, perimeter of the track = (30 + 150) x 2 = 360 metres So, speed of the car = (360/20) = 18 m/s Relative speed of the car with respect to the person = 18 + 5 = 23 m/s So, distance between the car and the person, 3 seconds before they cross each other = 23 x 3 = 69 metres
Salaries of A and B are in the ratio 5 : 7. If A’s salary increases by 20% and B’s salary decreases by 10%, what is the new ratio?
- Total number of students in a college is 960. The ratio of boys to girls is 3:5. The ratio of boys who passed to those who failed is 7:2. The ratio of girl...
A, B And C did certain investments and the ratio of their time periods is 3:2:7 respectively. The ratio of the profit of A, B, and C is 4:3:14 respectiv...
If the ratio of the sum invested and simple interest received after 1 year is 25:9 respectively, then find the rate of interest.
If the diagonal of a square is increased by 4 cm, its area increases by 56 cm2 . Find the ratio of the new area of the square to the initial ...
A box contains Rs. 930 in coins of Rs. 2, Rs. 5, and Rs. 8 denominations. The ratio of number of coins of Rs. 2, Rs. 5, and Rs. 8 is 6:5:7 respectively....
Ratio of present ages of mother and her son is 24:8 respectively. Father’s present age is 14 years more than that of mother. If the present average ag...
The ratio of the ages of A and B is 3:5. If the difference between their ages is 10 years, what is the sum of their ages?
The total number of cars to the total number of bikes in Showrooms P and Q is in the ratio 60:17. Additionally, the number of bikes in Showroom P to th...Samir distributed 625 gifts among 4 children. The first part of the child is twice the portion of the other child, three times the size of the third chi...
