# 12 Important Maths Problems with Solutions

Question 1:

what number should be added to - 7/8 to get 4/9

let the required number is x.

According to the question,

- 7/8 + x = 4/9

x=4/9+7/9

=(4+7)/9

=11/9

Required number=11/9

Question 2:

what number should be added to -5/12 to get 7/6

let the required number is x.

According to the question,

-5/12 + x = 7/6

x=7/6+5/12

=(14+5)/12

=19/9

Required number=19/12

Question 3:

what should be subtracted from -4/9 to get 5/12

let the required number is x.

According to the question,

-4/9-x=5/12

Or, -x=5/12+4/9

Or, x=(15+12)/36

Or, -x=37/36

Or,x=-37/36

Required number=-37/36

Question 4:

what number should be added to -5/7 to get -7/9

let the required number is x.

According to the question,

-5/7+x=-7/9

Or, x=-7/9 + 5/7

Or, x=(-49+45)/63

Or, x=-4/63

Required number=-4/63

Question 5:

what number should be subtracted from -2/3 to get -1/6

let the required number is x.

According to the question,

-2/3-x=-1/6

Or, -x=-1/6+2/3

Or, -x=(-1+4)/6

Or, -x=3/6

Or, -x=1/2

Or, x=-1/2

Required number=-1/2

Question 6:

what number should be added to 3/8 to get 7/9

let the required number is x.

According to the question,

3/8+x=7/9

Or, x=7/9-3/8

Or, x=(56-27)/72

Or, x=29/72

Required number=29/72

Question 7:

what number should be added to 3 by 8 to get minus 1 by 24

or

what number should be added to 3/8 to get - 1/24

or

what should be added to 3/8 to get-1/24

let the required number is x.

According to the question,

3/8+x=1/24

Or, x=1/24-3/8

Or, x=(1-9)/24

Or, x=-8/24

Or, x=-1/3

Required number=29/72

Question 8:

simplify: 2/3 + -4/5 + 7/15 + -11/20

2/3 + -4/5 + 7/15 + -11/20

=2/3 - 4/5 + 7/15 - 11/20

=(40-48+28-22)/60

=-2/60

=-1/30

Question 9:

what rational number should be added to -5/11 to get -7/8

let the required number is x.

According to the question,

-5/11+x=-7/8

Or, x=-7/8+5/11

Or, x=(-56+40)/88

Or, x=-16/88

Or, x=-2/11

Required number=-2/11

Question 10:

which of the rational numbers 4/9, -5/6, -7/-12 and 11/-24 is the smallest?

4/9=0.4444444444……

-5/6=-0.833333333333………(smallest)

-7/-12=7/12=0.583333333333……..(greatest)

11/-24=-11/24=-0.4583333333333………

Question 11:

the product of two numbers is -20/9. if one of the numbers is 4, find the other.

Let other number=x

According to the question,

x * 4=-120/9

or, x=-30/9

or, x=-10/3

so, other number is 10/3.

Question 12:

which of the two rational numbers 5 / 7 or 3 / 5 is greater?

5/7=0.714285714

3/5=0.6

So, 5/7 is greater.