MOKASA I EXAMINATION 121/1 MATHEMATICS Paper 1

MOKASA I EXAMINATION
Kenya Certificate of Secondary Education
121/1
MATHEMATICS
Paper 1
March. 2025
2½ HOURS
SECTION I (50 MARKS)
Answer ALL questions in this section
1. Without using a calculator, evaluate;
(3 marks)
1
1
1
1 2
𝑜𝑓 3 + 1 (2 − )
2
2
2
2 3
3
1 1
𝑜𝑓 2 ÷
4
2 2
2. Solve for x in the equation.
(3 marks)
(2x – 1)
(2x – 1)
2
x 16
=1
3. A metallic solid cone has a base radius of 6.4 cm and slant height 15.8 cm. If the density of the
22
metal is 7.9 g⁄cm3 , calculate its mass in kg.(Take π= )
(3 marks)
7
4. Members of a group decided to raise K£100 towards a charity by contributing equal amount. Five
of them were unable to contribute. The rest had, therefore, to pay K£1 more each to raise the same
amount. How many members were in the group originally?
(3 marks)
5. The LCM of three numbers is 1512 and their GCD IS 6. If two of the numbers are 54 and 72, find
the least third possible number.
(3 marks)
6. The exterior angle of a regular polygon is equal to one-third of interior angle. Calculate the
number of sides of the polygon.