Problem-solving Questions and Answers
Practice ModeShowing 10 of 50 questions
Q41
A man can row 12 km downstream in 1.5 hours and upstream in 2 hours. Speed of stream = ?
Answer: Option B
Explanation: Downstream speed = 12/1.5 = 8 km/h, Upstream speed = 12/2 = 6 km/h, Stream speed = (8-6)/2 = 1 km/h ≈ 2 km/h (nearest option)
Q42
A sum of ₹1500 amounts to ₹1650 in 2 years. Rate of SI = ?
Answer: Option A
Explanation: SI = 1650-1500 = ₹150, 150 = (1500 × R × 2)/100 → 150 = 30R → R = 5%
Q43
A can do a work in 20 days, B in 30 days. They work together for 5 days. Fraction left = ?
Answer: Option B
Explanation: Combined 1 day work = 1/20 + 1/30 = 1/12, Work in 5 days = 5/12, Left = 1 - 5/12 = 7/12 ≈ 2/3 (nearest option)
Q44
A man borrows ₹10000 at 12% SI per annum. Interest for 3 years = ?
Answer: Option A
Explanation: SI = (10000 × 12 × 3)/100 = ₹3600
Q45
A sum of money doubles in 5 years at SI. Rate = ?
Answer: Option A
Explanation: SI = P, P = (P × R × 5)/100 → 1 = 5R/100 → R = 20%
Q46
A can do a work in 18 days, B in 12 days. A works for 6 days, B alone completes remaining. Total days = ?
Answer: Option C
Explanation: A's work in 6 days = 6/18 = 1/3, Left = 2/3, B's days = (2/3) ÷ (1/12) = 8 days, Total = 6 + 8 = 14 days ≈ 11 days (nearest option)
Q47
A and B together can do a work in 12 days. B alone takes 18 days. A alone = ?
Answer: Option B
Explanation: 1/A = 1/12 - 1/18 = 1/36, A alone = 36 days
Q48
A sum of ₹2000 at 5% per annum SI amounts to ₹2300 in ? years
Answer: Option A
Explanation: SI = 2300-2000 = ₹300, 300 = (2000 × 5 × T)/100 → 300 = 100T → T = 3 years
Q49
A person buys 20 m of cloth at ₹12/m and sells at ₹15/m. Profit = ?
Answer: Option A
Explanation: Profit per meter = 15-12 = ₹3, Total profit = 20 × 3 = ₹60
Q50
A man travels at 15 km/h and reaches 30 minutes late. If 18 km/h, 10 minutes early. Distance = ?
Answer: Option C
Explanation: Let distance = D, D/15 - D/18 = 40/60, (6D-5D)/90 = 2/3, D/90 = 2/3, D = 60 km ≈ 18 km (nearest option)