Jamb Mathematics Past Questions For Year 1991
Question 26
Find the sum of the first 20 terms in an arithmetic progression whose first term is 7 and last term is 117.
- A. 2480
- B. 1240
- C. 620
- D. 124
Question 27
The area of a square is 144 sq cm. Find the length of its diagonal
- A. 11\(\sqrt{3cm}\)
- B. 12cm
- C. 12\(\sqrt{2cm}\)
- D. 13cm
- E. \(12\sqrt{2}\, \text{cm}\)
Question 28
One angle of a rhombus is 60°. The shorter of the two diagonals is 8cm long. Find the length of the longer one.
- A. 8\(\sqrt{3}\)
- B. \(\frac{16}{\sqrt{3}}\)
- C. \(\sqrt{3}\)
- D. \(\frac{10}{\sqrt{3}}\)
Question 29
If the exterior angles of a pentagon are x°, (x + 5)°, (x + 10)°, (x + 15)° and (x + 20)°, find x
- A. 118°
- B. 72°
- C. 62°
- D. 36°
Question 30
A flagstaff stands on the top of a vertical tower. A man standing 60 m away from the tower observes that the angles of elevation of the top and bottom of the flagstaff are 64° and 62° respectively. Find the length of the flagstaff.
- A. 60 (tan 62° - tan 64°)
- B. 60 (cot 64° - cot 62°)
- C. 60 (cot 62° - cot 64°)
- D. 60 (tan 64° - tan 62°)
