WBCS Math Questions Set 7 with Answers

Submitted by Atanu Chaudhuri on Sun, 29/07/2018 - 21:20

$wbcs math questions arithmetic practice set 7$

7th selected WBCS math question set for Arithmetic practice

Solve 10 WBCS math questions set 7 in 10 mins. Verify results from answers. To solve the questions this quick you need to know how to solve in mind.

Questions are on time distance, race, number system, ratio, train running, time work, compound growth, componendo dividendo. It should be useful for prelims of other competitive exams also.

The solution set (linked at the end) explains how to solve the questions quickly in mind.

Answers to the questions are at the end.

WBCS math question set 7: time to answer 10 mins

Problem 1

A man gains 10% by selling an article at a certain price. If he sells it at double the price, the profit made is,

60%
20%
100%
120%

Problem 2

When 40% of a number is added to 42, the result is the number itself. The number is,

Problem 3

If $\displaystyle\frac{4}{5}$th of a cistern is filled in 1 minute, how much more time will be required to fill the rest of it?

10 sec
20 sec
12 sec
15 sec

Problem 4

If $a:b=c:d=e:f=1:2$, then $(3a+5c+7e):(3b+5d+7f)=\text{?}$.

$1:2$
$2:1$
$1:4$
$8:7$

Problem 5

The speed of a train 150m long is 50km/h. How much time will it take to pass a platform 600m long?

64 sec
60 sec
50 sec
54 sec

Problem 6

A can do a work in 20 days and B can do it in 12 days. B worked at it for 9 days. In how many days can A alone finish the remaining work?

Problem 7

If $(1^2 + 2^2 + 3^2+.....+10^2)=385$, then the value of $(2^2+4^2+6^2+.....+20^2)$ is,

$770$
$1155$
$385\times{385}$
$1540$

Problem 8

If $1.5x=0.04y$, then the value of $\left(\displaystyle\frac{y-x}{y+x}\right)$ is,

$\displaystyle\frac{73}{77}$
$\displaystyle\frac{703}{77}$
$\displaystyle\frac{73}{770}$
$\displaystyle\frac{730}{77}$

Problem 9

The population of a town increases annually by 5% . If it is 15435 now, the population two years ago was,

13700
14000
15000
14800

Problem 10

In a 100m race, A beats B by 10m and C by 13m. In a race of 180m between the three, B will beat C by,

6m
5m
5.4m
4.5m

To know how to solve the problems quickly in mind and detailed explanation, you should refer to the corresponding solution set, Solution to 7th WBCS Math Question set for Arithmetic Practice.