Exercise

The grades obtained by 30 students of class VII are as follows:

$A^{+}\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }A\mathit{,}\mathit{ }B\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }B\mathit{,}\mathit{ }B\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }A\mathit{,}\mathit{ }A\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }B\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }A\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }B\mathit{,}\mathit{ }B\mathit{,}\mathit{ }A\mathit{,}\mathit{ }A\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }B\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }B\mathit{,}\mathit{ }{B}^{+}\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }{A}^{+}\mathit{,}\mathit{ }A$ If a student has been selected at random, then find the probability that he has obtained grade $A^{+}$

Manvi says that she got $16$ more marks than $4$ times the number of marks scored by Aashi. Form an equation which gives the marks scored by Aashi, if Manvi scored $72$ marks.

A rectangular piece of land is to be sold off in smaller pieces. The total area of the land is $2^{17}$ sq. miles. The pieces to be cut out are ${16}^2$ sq. miles in size. How many smaller pieces of the land can be sold at the given size?

Sushma sells an article at a loss of $12\%$. If she had sold it for $₹50.80$ more, then she would have earned a profit of $8\%$. Find the cost price of the article.

A rectangular grassy land is $65 \mathrm{m}$ long and $50 \mathrm{m}$ broad. It is surrounded by $3 \mathrm{m}$ wide path. Find the cost of gravelling the path at $₹2.50$ per ${\mathrm{m}}^2$

The number of students in a school increased by $8⁒$ annually. If there are $71280$ students in the school, then how many students were there last year?

The ages of Ruchi and Suchi are in the ratio $6:1$ The sum of their ages is $56$ years. What is the ratio of their ages after  $6$years?

In an examination, one should get $36⁒$ of the maximum marks to pass. A student obtained $113$ marks and is declared fail by $85$ marks. The maximum marks are _____