This page 10th cbse maths solution for exercise 3.5 part 4 is going to provide you solution for every problems that you find in the exercise no 3.5

10th CBSE maths solution for Exercise 3.5 part 4

(iv) Places A and B are 100 km apart on a highway. One car
starts from A and another from B at the same time. If the car travel in the
same direction at different speeds, they meet in 5 hours. If they travel
towards each other ,they meet in 1 hour. What are the speeds of the two cars?

Solution:

Let “x km/hr” be the speed of 1st car

Let “y km/hr” be the speed of the 2nd car

Time = Distance/Speed

Speed of both cars while they are traveling in the same
direction = (x – y)

Speed of both cars while they are traveling in the opposite
direction = (x + y)

5 (x – y) = 100

x – y = 100/5

x - y = 20 ------(1)

1(x + y) = 100

x + y = 100 ------(2)

x = 120/2

x = 60

Substitute x = 60 in the first or second equation to get the
value of y

60 – y = 20

-y =
20 – 60

-y =
-40

Y =
40

Therefore the speed of first car = 60 km/hr

Speed of second car = 40 km/hr

(v) The area of a rectangle gets reduced by 9 square units,
if its length is reduced by 5 units and breadth increased by 3 units. If we
increase the length by 3 units and the breadth by 2 units, the area increases
by 67 square units. Find the dimensions of the rectangle.