JEE Main 2023 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 10 April 2023, Shift 1, Maths Q7

Question 7 of 90 in this shift, Maths question 7 of 30, Section A.

A square piece of tin of side 30 cm is to be made into a box without top by cutting a square from each corner and folding up the flaps to form a box. If the volume of the box is maximum, then its surface area (in cm

^2

) is equal to

(1) $675$
(2) $1025$
(3) $900$
(4) $800$ Official answer

Official answer

Option 4

NTA final key.

Chapter: Application of Derivatives
Topic: Maxima and Minima
Idea tested: Optimization Problems

Same idea in other shifts

Asked 13× in all

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27 Jun 2022, Shift 1 · Q7The lengths of the sides of a triangle are $10+x^2$ , $10+x^2$ and $20-2x^2$ . If for $x=k$ , the area of the triangle is maximum, then…MediumSingle correct
29 Jun 2022, Shift 1 · Q14A wire of length 22 m is to be cut into two pieces. One of the pieces is to be made into a square and the other into an equilateral…MediumSingle correct
30 Jun 2022, Shift 1 · Q8If $xy^4$ attains maximum value at the point $(x, y)$ on the line passing through the points $(50+\alpha, 0)$ and $(0, 50+\alpha)$ ,…MediumSingle correct
26 Aug 2021, Shift 1 · Q84A wire of length 36 m is cut into two pieces, one of the pieces is bent to form a square and the other is bent to form a circle. If the…MediumNumerical value
27 Aug 2021, Shift 1 · Q66A wire of length 20 m is to be cut into two pieces. One of the pieces is to be made into a square and the other into a regular hexagon.…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.