9
Q:

# 50 men can build a tank in 40days, but though they begin the work together, 5 men quit every ten days. The time needed to build the tank is ?

 A) 50 days B) 48 days C) 47.5 days D) 49 days

Explanation:

50 men can build a tank in 40 days
Assume 1 man does 1 unit of work in 1 day
Then the total work is 50×40 = 2000 units

50 men work in the first 10 days and completes 50×10 = 500 units of work
45 men work in the next 10 days and completes 45×10 = 450 units of work
40 men work in the next 10 days and completes 40×10 = 400 units of work
35 men work in the next 10 days and completes 35×10 = 350 units of work
So far 500 + 450 + 400 + 350 = 1700 units of work is completed and

remaining work is 2000 - 1700 = 300 units

30 men work in the next 10 days. In each day, they does 30 units of work.

Therefore, additional days required = $\inline \fn_jvn \small \frac{300}{30}=10$

Thus, total 10+10+10+10+10 = 50 days required.

Q:

One girl can eat 112 chocolates in half a minute, and her boy friend can eat half as many in twice the length of time. How many chocolates can both boy and girl eat in 12 seconds ?

 A) 44 B) 32 C) 56 D) 49

Explanation:

Girl eats 112 chocolates in 30 sec
so she can eat in 12 sec is 12 x 112/30 = 44.8 chocolates.

Her boy friend can eat one-half of 112 in twice of 30 sec
so he can eat 56 in 60 sec
Then he can eat in 12 sec is 56 x 12/60 = 11.2 chocolates.

Hence, together they can eat
=> 44.8 + 11.2
56 chocolates in 12 seconds.

4 9
Q:

Two boys and a girl can do a work in 5 days, while a boy and 2 girls can do it in 6 days. If the boy is paid at the rate of 28\$ a week, what should be the wages of the girl a week ?

 A) 24 \$ B) 22 \$ C) 16 \$ D) 14 \$

Explanation:

Let the 1 day work of a boy=b and a girl=g, then
2b + g = 1/5 ---(i) and
b + 2g = 1/6 ---(ii)
On solving (i) & (ii), b=7/90, g=2/45
As payment of work will be in proportion to capacity of work and a boy is paid \$ 28/week,
so a girl will be paid 28x $\inline \fn_jvn \frac{\frac{2}{45}}{\frac{7}{90}}$ = 16 \$.

2 8
Q:

A constructor estimates that 4 people can paint Mr. Karthik's house in 6 days. If he uses 5 people instead of 4, how long will they take to complete the job ?

 A) 3 days B) 26/3 days C) 13/4 days D) 24/5 days

Explanation:

we know that m1 x d1 = m2 x d2
=> 4 x 6 = 5 x d
where d = no. of days taken by 5 men to paint
d = 24/5 days.

3 15
Q:

6 boys and 8 girls can do job in 10 days , 26 boys & 48 women do work in 2 days. Find time taken by 15 boys and 20 girls to do same work ?

 A) 2 days B) 3 days C) 4 days D) 5 days

Explanation:

One day work of 6 boys and 8 girls is given as 6b + 8g = 1/10 -------->(I)
One day work of 26 boys and 48 women is given as 26b + 48w = 1/2 -------->(II)

Divide both sides by 2 in (I) and then multiply both sides by 5
Now we get
15b + 20g = 1/4.
Therefore, 15 boys and 20 girls can do the same work in 4 days.

4 12
Q:

In a regular week, there are 5 working days and for each day, the working hours are 8. A man gets Rs. 2.40 per hour for regular work and Rs. 3.20 per hours for overtime. If he earns Rs. 432 in 4 weeks, then how many hours does he work for ?

 A) 145 B) 165 C) 175 D) 135

Explanation:

Given that
working days = 5;
working hours = 8;
A man get rupess per hour is Rs.2.40;
So in one day the man get total rupees is 2.40 x 8 = 19.2
So in 5 days week the man get total rupees is 19.2 x 5 = 96
So in 4 week the man get total rupees is 96 x 4 = 384
So the man worked for = 160hours in 4 weeks
But given that the man earned Rs.432
Hence remaning money is (432-384 = 48)which is earn by doing overtime work
Overtime hours is = 48/3.20 = 15
So total worked hours is = 15 + 160 = 175.