Question
The cost of 3 pens, 8 pencils,
and 12 erasers at a stationery shop is Rs 90. At the same shop, the cost of 5 pens and 8 erasers is Rs 45 more than 10 pencils. By how much amount (in Rs.) does the cost of 60 pencils and 3 erasers exceed the cost of 10 pens?Solution
ATQ,
Let the cost of a pen be x, a pencil be y, and an eraser be z. From the information: 
To find 60y+3z−10x: Combine (1) and (2), solve for the required expression, yielding the answer as Rs 75.Â
From a point on the ground, the angle of elevation of the top of a tower is 30°. After moving 20 m closer to the tower in a straight line, the angle of...
The angle of depression from the top of a light-house of two boats are 60° and 30° towards the west, if the two boats are 60m apart, then the height ...
Now a chord of a circle is such that AB = 10 cm. If the diameter of the circle is 20 cm, then the angle subtended by the chord at the center is.
The angle of depression of a point on the ground as seen from the top of a tower, 65 feet high, is 45°. Find the distance of the point on the ground fr...
From the top of a straight pillar 20 meters high, the angle of elevation of the top of a straight tower was 45°. If the tower was 70 meters high, then ...
From the top of an upright pole 30√3 feet high, the angle of elevation to the top of an upright tower was 60°. If the foot of the pole was 55 feet aw...
From a watch tower of 150 m height, the angles of depression of two cliffs in a horizontal line through the base of the tower are 45° and 30°. Find th...
The angle of elevation of an aeroplane from a point on the ground is 60°. After 20 seconds flight the elevation changes to 30°, if the aeroplane...
The distance between two parallel poles is 65√3 m. The angle of depression of the top of the second pole when seen from the top of first pole is 3...
The length of the shadow of a vertical tower increases by 9 m on horizontal ground when the height of the sun changes from 45° to 30 ° , then fi...
Relevant for Exams:
