West Bengal Board Solutions for Chapter: Revision of Previous Knowledge, Exercise 5: Let's do Ourselves

If the cost of a dozen eggs is $₹48$. Let's find the cost of $32$ eggs.

In $120 \mathrm{kg}$ of mixed fertilizer, the amount of urea and potash are $60\%$ and $40\%$ respectively. Let's find and write, how many kgs of fertilizers of each type are present in the mixed fertilizer.

The cost of my school exercise book was $₹10$. Now I buy the same exercise book for $₹12$. Let's calculate the percentage increase in the price of the exercise book.

The bus fare from Sumitra's house to school was $₹4$. Now to travel the same distance she has to pay $₹6$. Let's find the percentage rise in bus fare.

Due to the increase in the price of sugar, the amount of sugar bought for $₹125$ is now bought for $₹150$. Let us calculate the percentage rise in the price of sugar at present.

Rojina worked out $90$ sums in one day. Shefali did $65$ sums at the same time. Let's find what percentage of sums Rojina did more than Shefali. Let's find the per­centage of sums Shefali did less than Rojina during that period of time.

Suhasbabu spends $66\frac{2}{3}\%$ of his monthly income. If he spends $₹3250$ per month, then what is his monthly income. Let's calculate.

Let's colour $10\%$ of the squares red and $40\%$ of square yellow in the squared figure given below.