A can do a work in 60 days and B can do the same work in 40 days. They work together for 12 days and then 'A' goes away. In how many days will 'B' finish the remaining work?
16 days
20 days
25 days
28 days
24 days
Answer: Option B.
Work done by A and B in 12 days is
= 12 * 5/120 = 1/2
Therefore Remaining work = 1- 1/2 = 1/2work
B does 1/40 work in one day
Therefore B does 1/2 work in 40*1/2 =20days
32 49 83 151 287 559?
1118
979
1103
1120
None of these
Answer: Option C.
32 49 83 151 287 559 ?
+17 +34 +68 +136 +272 +544
+17 +34 +68 +136 +272
So answer is 559 + 544 = 1103.
462 552 650 756 870 992?
1040
1122
1132
1050
None of the Above
Answer: Option B.
462 552 650 756 870 992
+90 +98 +106 +114 +122 +130
+8 +8 +8 +8 +8
So next number is 992 + 130 = 1122.
The average age of a woman and her daughter is 42 years. The ratio of their ages is 2 : 1 respectively. What is the daughter's age?
28 years
48 years
52 years
31 years
None of these
Answer: Option B.
Let the age of mother be M and that of her daughter be D Therefore, [M+D]/2 = 42 [M/D]=2/1 and Solving the abvoe equations we get D = 28 yrs.
The price of sugar is increased by 25%.Find by how much percent the consumption of sugar be decreased so as not to increase the expenditure?
25%
40%
20%
30%
None of these
Answer: Option C.
Using the formula to calculate % decrease as [R/(100+R)]x100 where R = percentage increase in price, we get
Required % decrease in consumption = 25/125 MULTIPLIED 100 = 20%.
A car travels a distance of 45 km at the speed of 15 km/hr. It covers the next 50 km of its journey at the speed of 25km/hr and the last 25 km of its journey at the speed of 15 km/hr. What is the average speed of the car?
40 km/hr
24 km/hr
15 km/hr
18 km/hr
None of these
Answer: Option D.
We know, Average speed = Total distance travelled / Total time taken Average = [45+50+25]/[3+2+{25/15}] = 18 kmph
A car travels a distance of 170 km in 2 hours partly at a speed of 100 km/h and partly at 50 km/h. The distance travelled at a speed of 50 km/h is?
50 km
40 km
30 km
60 km
None of these
Answer: Option C.
Suppose he covers x km at 100 kmph
So he covers 170-x at 50 kmph
So {X/100}+{170-X}/50=2
Solving this equation, we get x = 140.
So he covers 30km at 50 kmph.
Even after reducing the marked price of a transistor by Rs. 32, a shopkeeper makes a profit of 15%. If the cost price be Rs. 320, what percentage of profit would he have made if he had sold the transistor at the marked price?
25%
20%
10%
15%
None of these
Answer: Option A
.Let x be the marked price,
So x - 32 = 320 X 1.15
x = 400.
So required value is
400 = 320 (1 + profit/100),
So profit is 25%
The ratio of the present ages of A and B 9 : 5. Five years earlier the ratio of their was 2 : 1. What is the average of their present ages?
20 years
25 years
35 years
40 years
None of these
Answer: Option C.
A/b=9/5; i.e. 5a = 9B ..........(i)
A-5/B-5 = 2/1; i.e. A-5 = 2B .........10
∴A - 2B = -5 ...................(ii)
From equation (i) and (ii), A = 45, B = 25
∴ Average =45+25/2 = 70/2 = 35.
20 boys and 32 girls form a group for social work. During their membership drive same no. of boys and girls joined the group. How many members does the group have now, if the ratio of boys to girls is 3:4 respectively?
75
86
68
82
None of The above
Answer: Option E.
Let x be the new boys as well as girls , Therefore
[20+X]/[32+X]=3/4
Solving this we get x = 16
So total will be 36 + 48 = 84.