In farm there is 2 ducks,6 cats ,4 dogs . Each weight of duck 4 kg, cat 4 kg and dog 7 kg what is the average weight of all animals?

={( number of ducks Ã— weight)+( number of dogs x weight)}/ total animals

= 5 kilogram is average weight of all animals.

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The sum of how many terms of the series 6 + 12 + 18 + 24 + ... is 1800 ?

This is an A.P. in which a = 6, d = 6 and Sn = 1800

Then, n/2[2a + (n - 1)d] = 1800

n/2[2 x 6 + (n - 1) x 6] = 1800

3n (n + 1) = 1800

n(n + 1) = 600

n2 + n - 600 = 0

n2 + 25n - 24n - 600 = 0

n(n + 25) - 24(n + 25) = 0

(n + 25)(n - 24) = 0

n = 24

Number of terms = 24.

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The present age of lewis and Brown are in ratio 1:2. Three years from now, the ages will in ratio 3:5. Find the age of lewis after five years?

Let's present age

Lewis =l

Brown=b

l/b=1:2

l-2b=0

After three years

l+3/b+3=3:5

5l-3b=6

l=6

b=12

After 5 years

l=11

b=17

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In following number series, two terms have been put within brackets. Choose the appropriate option

Choose the appropriate option 4, 7, (9), 10, 13, 15, (16), 19

Choose the appropriate option 4, 7, (9), 10, 13, 15, (16), 19

The correct sequence is is + 3, + 2, + 1, + 3, + 2, + 1, + 3.

Clearly, both the terms 9 and 16 are correct..

In a fort there is enough food sufficient for 1200 man 5 days how long the food would have last for if there would would have been thousand men.

Let food will last for X days.

As men and days are inversely proportional to each other so

X/5=1200/1000

X=1.2*5=5

X=6

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In a family, there are 6 member A, B, C, D, E and F. A and B are married couple, A being the male member, D is only son of C, who is brother of A. E is the sister of D. B is daughter in law of F, whose husband has died How is F related to A?

A is male and married to B. So, A is husband and B is a wife. C is brother of A. D is a son of C.E, who is sister of D will be daughter of C. B is the daughter in law of F whose husband has died means F ia the mother of A. Clearly, F is mother of A..