For the following questions answer them individually
Cost of 8 pencils, 5 pens and 3 erasers is Rs 111. Cost of 9 pencils, 6 pens and 5 erasers is Rs 130. Cost of 16 pencils, 11 pens and 3 erasers is Rs 221. What is the cost (in Rs) of 39 pencils, 26 pens and 13 erasers?
If $$2x + 3y - 5z = 18, 3x + 2y + z = 29$$ and $$x + y + 3z = 17$$, then what is the value of $$xy + yz + zx$$?
PQR is an equilateral triangle whose side is 10 cm. What is the value (in cm) of the inradius of triangle PQR?
What is the area (in $$cm^2$$) of the circumcircle of a triangle whose sides are 6 cm, 8 cm and 10 cm respectively?
In the given figure, MNOP is a parallelogram. PM is extended to Z. OZ intersects MN and PN at Y and X respectively. If OX = 27 cm and XY = 18 cm, then what is the length (in cm) of YZ?
ABCD is a trapezium in which AB is parallel to CD and AB = 4(CD). The diagonals of the trapezium intersects at O. What is the ratio of area of triangle DCO to the area of the triangle ABO?
In the given figure, ABC is an equilateral triangle. Two circles of radius 4 cm and 12 cm are inscribed in the triangle. What is the side (in cm) of an equilateral triangle?
In the given figure. SX is tangent. SX = OX = OR. If QX = 3 cm and PQ = 9 cm, then what is the value (in cm) of OS ?
PAB and PCD are two secants to a circle. If PA = 10 cm, AB = 12 cm and PC = 11 cm, then what is the value (in cm) of PD?
Triangle PQR is inscribed in a circle such that P, Q and R lie on the circumference. If PQ is the diameter of the circle and $$\angle PQR = 40$$°, then what is the value (in degrees) of $$\angle QPR$$?