Question
Ravi invests Rs. 2,000 on simple interest at 'a%' p.a.
for 4 years and earned an interest of Rs. 800. His friend Vinay invests Rs. 4,800 on simple interest at 30% p.a. for 'b' months and earned an interest of Rs. 3,600. Find the product of 'a' and 'b'.Solution
Simple interest = (Principal × rate × time) ÷ 100 ATQ, 800 = 2,000 × a × 4 ÷ 100 Or, 800 = 80a So, 'a' = 10 And, 3,600 = (4,800 × 30 × b) ÷ (12 × 100) ...... (since, time is in months) Or, 3,600 = 120b Or, 'b' = 30 Therefore, the required product = (a × b) = 10 × 30 = 300
16, 27, 44, 63, 98, 139
210, 140, 105, 84, 70, 63, 52.5Â
0 7 26 63 126 215
...32, 46, 88, 158, 256, 380
Find the wrong number in the given number series.
32, 48, 84, 146, 248, 392
100, 75, 59, 55, 46, 45
21Â Â Â Â Â Â Â Â Â Â 32Â Â Â Â Â Â Â Â Â Â 54Â Â Â Â Â Â Â Â Â Â 86Â Â Â Â Â Â Â Â Â Â 131Â Â Â Â Â Â Â Â 186
...131, 212, 261, 286, 295, 299
Find the wrong number in the given number series.
3, 7, 22, 89, 445, 26771, 2, 8, 48, 386, 3840