Question
The average height of the boys in a class is 160 cm,
while the average height of the girls is 155 cm. The overall average height of all students in the class is 157 cm, and the total number of students is 180. Can you determine how many boys are there in the class?Solution
Let number of boys in the class be ‘b’ and number of girls in the class be ‘180 – b’. ATQ; {160 × b + 155 × (180 – b)}/180 = 157 Or, (160b + 155 × 180 – 155b) = 157 × 180 Or, 160b – 155b = 2 × 180 Or, 5b = 360 Or, b = 72 Therefore, number of boys in the class are 72.
Select the correct combination of mathematical signs that can sequentially replace the “@” sign and balance the following equation.
12@5@7@2@...
If 65 + 54 = 2, 71 + 62 = 10, then 73 + 83 = ?
If A denotes ‘addition’, B denotes ‘multiplication’, C denotes ‘subtraction’, and D denotes ‘division’, then what will be the value of t...
In a certain code language, '+' represents '÷', ' - ' represents ' X ', '÷' represents '+' and ' X ' represents '-'. Find out the answer to the follow...
Select the correct combination of mathematical signs to replace the '@' signs and balance the given equation.
22 @ 6 @ 18 @ 17 @ 2
A shopkeeper sells rice in such a way that the selling price of 950 gm is the same as the cost price of one kilogram. Find his gain percent.
If '+' means 'division', ' X ' means 'addition', ' - ' means 'multiplication' and '÷' means 'subtraction', then what is the value of the following expr...
If ‘+’ stands for ‘division’; ‘×’ stands for ‘addition’; ‘–’ stands for ‘multiplication’; ‘÷’ stands for ‘subtraction�...
If ‘÷’ means ‘-’, ‘-’ mean ‘+’, ‘+’ means ‘×’ and ‘×’ means ‘÷’, compute the value of the expression:
135 × ...
Which of the following interchange of sign would make the given equation correct?
45 × 9 + 5 ÷ 4 = 25
