Mathematics Mcqs

A sum of Rs. 12,500 amounts to Rs. 15,500 in 4 years at the rate of simple interest What is the rate of interest ? Read More »

A sum of Rs. 12,500 amounts to Rs. 15,500 in 4 years at the rate of simple interest What is the rate of interest ?

A. 3%
B. 4%
C. 5%
D. 6%
S.I. = Rs. (15500 – 12500) = Rs. 3000.
Rate = ( 100 X 3000/12500 X 4 )% = 6%.

A sum of money amounts to Rs 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is :

A sum of money amounts to Rs 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is : Read More »

A sum of money amounts to Rs 9800 after 5 years and Rs. 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is :

A. 5%
B. 8%
C. 12%
D. 15%
S.I. for 3 years = Rs. (12005 – 9800) = Rs. 2205. S.I. for 5 years = Rs. ( 2205/3 X 5 ) = Rs. 3675. So Principal = Rs. (9800 – 3675) = Rs. 6125. Hence, rate = ( 100 X 3675/6125 X 5 X 5 )% = 12%.

A sum of money trebles itself in 15 years, 6 months. In how many years would it double itself ?

A sum of money trebles itself in 15 years, 6 months. In how many years would it double itself ? Read More »

A sum of money trebles itself in 15 years, 6 months. In how many years would it double itself ?

A. 6 years 3 months
B. 7 years 9 months
C. 8 years 3 months
D. 9 years 6 months

What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years ?

What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years ? Read More »

What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years ?

A. 1 : 3
B. 1 : 4
C. 2 : 3
D. Data inadequate
Let the principal be P and rate of interest be R%. So Required ratio = [(P x R x 6/100) / (13 x R x 9/100)] = 6PR/9PR = 6/9 = 2 : 3

An automobile financier claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes :_________?

An automobile financier claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes :_________?

A. 10%
B. 10.25%
C. 10.50%
D. None of these
Let the sum be Rs. 100. Then, S.I. for first 6 months = Rs. ( 100 X 10 X 1/100 X 2 ) = Rs. 5. S.I. for last 6 months = Rs. ( 105 X 10 X 1/100 X 2 ) = Rs. 5.25. So, amount at the end of 1 year=Rs.(100 + 5 + 5.25) = Rs. 110.25 Effective rate = (110.25 – 100) = 10.25%.

The top of a 15 metre high tower makes an angle of elevation of 60° with the bottom of an electric pole and angle of elevation of 30° with the top of the pole. What is the height of the electric pole ?

The top of a 15 metre high tower makes an angle of elevation of 60° with the bottom of an electric pole and angle of elevation of 30° with the top of the pole. What is the height of the electric pole ?

A. 5 metres
B. 8 metres
C. 10 metres
D. 12 metres

The angle of elevation of the sun, when the length of the shadow of a tree is √3 times the height of the tree, is :________?

The angle of elevation of the sun, when the length of the shadow of a tree is √3 times the height of the tree, is :________? Read More »

The angle of elevation of the sun, when the length of the shadow of a tree is √3 times the height of the tree, is :________?

A. 30°
B. 45°
C. 60°
D. 90°
Let AB be the tree and AC be its shadow.
Let ∠ACB = θ.
Then, AC/AB = √3
Cot θ = √3
θ = 30°

From a point P on a level ground, the angle of elevation of the top of a tower is 30°. If the tower is 100 m high, the distance of point P from the foot of the tower is :_________?

From a point P on a level ground, the angle of elevation of the top of a tower is 30°. If the tower is 100 m high, the distance of point P from the foot of the tower is :_________? Read More »

From a point P on a level ground, the angle of elevation of the top of a tower is 30°. If the tower is 100 m high, the distance of point P from the foot of the tower is :_________?

A. 149 m
B. 156 m
C. 173 m
D. 200 m
Let AB be the tower. Then, ∠APB = 30° and AB = 100 m, AB/AP = tan 30° = 1/√3 AP = (AB X √3)= 100√3 m. = (100 X 1.73) m = 173 m.

If the height of a pole is 2√3 metres and the length of its shadow is 2 metres, find the angle of elevation of the sun.

If the height of a pole is 2√3 metres and the length of its shadow is 2 metres, find the angle of elevation of the sun. Read More »

If the height of a pole is 2√3 metres and the length of its shadow is 2 metres, find the angle of elevation of the sun.

A. 50°
B. 60°
C. 70°
D. 80°
Let AB be the pole and AC be its shadow. Let angle of elevation, ∠ACB = θ. Then, AB = 2√3m, AC = 2 m. tan θ = AB/AC = 2√3/2 = √3 θ = 60°. So,the angle of elevation is 60°