Maths Question Bank

Maths Practice Question

Grade 7th and 8th

Q1 In an examination,96% of the candidates passed and 50 failed. What is the number of candidates who appeared for the examination.
Ans Given

Passed candidates =96%

Total appeared =100%

Faild=100-96=4%

According to question failed =50

So
4%=50

1%=50/4

1%=12.5

Total=100x12.5=1250

Total candidates appeared in examination =1250

Q2 If the ratio of circumferences of two circles is 4:9, what is the ratios of their areas?(Ans 2:3)

Q3 If the perimeter of a square increases by 25%, what is the increase in its
area?
Let the side of square be x.

Perimeter of square = 4x

Increase in perimeter = 25% of 4x


New perimeter = 4x +x = 5x

Let the new side be y.

4y = 5x





ans 

Q4 To John put his hand watch on the table in such a way that  at  6 pm hour hands point to East. In which direction the minute hand will point at 9:15 PM?

Ans At 6pm the hour hand is at 6. It is given that the direction is north wrt to John. That means John is sitting on 12 side facing the watch.

Now considering centre of the watch as the point of reference , 6 is in north, 3 (15 min) is in west. At 9.15 min hand will be in WEST.

Q5 Andy walked 35m towards south. The he turned to his left and walked 25 m. He turned to his left and walked 12m. What distance he from the starting point and in which direction?(Ans square root 1154 and north west)

Q6 Two-fifth of one-fourth of three-seventh of a number is 15. What is the half of that number?
Ans 2/5×1/4×3/7 x = 15
6/140 x = 15
x = (15 × 140)/6
x = 350
Half of 350 = 175

Q7 Two numbers are such that the ratio between them is 4:7. If each is increased by 4, the ratio becomes 3:5. Find the larger number.(Ans 56)

Q8 The first angle of a triangle is three times as great as the second angle. The third angle measures 12 degrees less than twice the second angle.
Ans Since angle 2 is being compare to both angle 1 and angle 2, let

∠2 = x

∠1 = 3x

∠3 = 2x - 12

Since there are 3 angles, we can assume we will have a triangle.  The sum of the angles of any triangle is equal 180 degrees.

x + 3x + (2x - 12) = 180

x + 3x + 2x - 12 = 180

6x - 12 = 180

6x = 192

  x = 32

Substitute this x value into the three angles.

∠1 = 96 degrees

∠2 = 32 degrees

∠3 = 52 degrees

Q9 Peter is three time as old as Anna. The sum of their ages five years from now will be twice Peters present age. The age of Peter is?( Peter Age is 15, Anna is 5 Years old)

Q10 The ratio of two smaller sides of a triangle is 4:3. A rectangle is formed on the largest side of the triangle in such a way that largest side will be the length of the rectangle. The breadth of rectangle is four fifth of its length. Find the length of shortest side of triangle  if the perimeter is 1.8 m.
Ans : Ans let the base of triangle be 4x , height be 3x and the length of rectangle or hypotenuse of triangle be h and breadth of rectangle be 4/5h
h=(3⋅x)2+(4⋅x)2−−−−−−−−−−−−−√h=(3⋅x)2+(4⋅x)2
h=5x
so, breath will be4/5⋅5⋅x=4⋅ax
perimeter = 180 cm 2⋅(l+b)=180
5x+ 4x=180
9x=180
x=10
so shortest side be the perpendicular 3x=3 x 10 = 30 cm

Q11 A group of boys went to a restaurant for lunch,where 40% of the boys ordered pizza and the remaining six boys ordered  burger. How many boys went to the restaurant.

Q12 When a number is reduced by 4, it becomes 80% of itself. find the number.
(Ans 20)

Q13  One of the angles of a certain triangle is three times the second angle and third is 16 smaller than the first. Find the three angles.

Q 14 A frog is at the bottom of a 20 foot well. Each day it jumps up 4 feet but each night it slips back 3 feet. How many days are required for the frog to reach the top of the well?

Ans 4-3=1 ft. gain each day.
15 days=15 ft. gained.
The 16th. day 15+4=19-3=16 ft.
The 17th. day 16+4=20 ft. & out for the frog on the 17th. day.

Q 15 Ankur works in a ten story office building. He gets on at the fourth floor and rides to the floor. He then goes down seven floors, rides up four floors. If the display of the lift indicating position is malfunctioning. Where is Ankur now and how many floors should he move in order to reach the first basement?

Q16  The melting point of Hg(mercury) is -39 degree Celsius. The freezing point of alchohol is -90 degree Celsius. How much more is the melting point of Hg as compared to freezing point of alcohol?

Q 17 A T.V. was sold at 19/24 of its original price. If the original price was INR 12,000    . Calculate the selling price of the T.V. Also calculate discount given.

Q 18 In a bracelet only 0.88 part of 22.5g overall bracelet is made of gold. If the bracelet is cut into five equal pieces. How much gold is there in each piece?

Q 19 There are 120 seats in the balcony of a theatre. If this is 1/5th of the total seat, what is total number of seats in the theatre?
Q 20 Give 3 integers whose sum is -12, of these  there should be 2 negative integers and 1 positive integer.
Q 21 The temperature of a place at 12 noon was 14 degree Celsius. If it decreased by 3 degree Celsius each hour, what was the temperature at 8 pm?

Q 22 A boy has INR 35 in his bank account, He deposits INR 50 everyday for the month of July. What will be the amount in his account  at the end of 10 days?

Q 23 A man travelled 50 km to east of Meerut and then 90 km to west of it. How far from Meerut was he finally?
Q24 A carton contains 16 boxes of nails and each box weighs    kg. How much  would a carton of nails weigh?
Q25  Sapna earns INR 88000 per month. She spends  of her income and deposits rest of money in a bank. How much money does she deposits in the bank each month.

Q 26  If the cost of  liters of water is INR , Find its cost per litre?

Q27 Solve

(-22)-[(-23)-(-17)-(-61)]
=(-22)-[(-23)+17+61]
=(-22)-[55]
=-22-55
=-77